Toxic elements. The most toxic elements of the Unified State Examination on garlic for the human body
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Toxic elements (in particular, some heavy metals) constitute a large and toxicologically very dangerous group of substances. Usually 14 elements are considered: Hg (mercury), Pb (lead), Cd (cadmium), As (arsenic), Sb (antimony), Sn (tin), Zn (zinc), Al (aluminum), Be (beryllium), Fe (iron), Cu (copper), Ba (barium), Cr (chromium), Tl (thallium). Of course, not all of the listed elements are poisonous; some of them are necessary for the normal functioning of humans and animals. Therefore, it is often difficult to draw a clear line between substances that are biologically necessary and substances harmful to human health.
In most cases, the implementation of a particular effect depends on concentration. When the optimal physiological concentration of an element in the body increases, intoxication, and a deficiency of many elements in food and water can lead to quite severe and difficult to recognize deficiency phenomena.
The dependence of the harmful or beneficial effects of some elements on concentration is shown in Fig. 11.3.
For substances belonging to the so-called supertoxicants, the plateau characterizing the norm is absent (or very short), and the steepness of the descending branch characterizes the toxicity of the substance (Fig. 11.4).
Pollution of water bodies, atmosphere, soil, agricultural plants and food products with toxic metals occurs due to:
Emissions from industrial enterprises (especially coal, metallurgical and chemical industries);
Emissions from urban transport (meaning lead pollution from combustion leaded gasoline);
Use of low-quality internal coatings in canning production and violation of solder technology;
Contact with equipment (a very limited number of steels and other alloys are allowed for food purposes).
For most products, maximum permissible concentrations (MAC) of toxic elements have been established; more stringent requirements are imposed on children's and dietary products.
The most dangerous of the above elements are mercury (Hg), lead (Pb), cadmium (Cd).
- one of the most dangerous and highly toxic elements, which has the ability to accumulate in plants and in the body of animals and humans, i.e. it is a poison of cumulative action.
The toxicity of mercury depends on the type of its compounds, which are absorbed, metabolized and excreted differently from the body. The most toxic short-chain alkylmercury compounds are methylmercury, ethylmercury, and dimethylmercury. The mechanism of the toxic effect of mercury is associated with its interaction with sulfhydryl groups of proteins. By blocking them, mercury changes the properties or inactivates a number of vital enzymes. Inorganic mercury compounds disrupt the metabolism of ascorbic acid, pyridoxine, calcium, copper, zinc, selenium; organic - metabolism of proteins, cysteine, ascorbic acid, tocopherols, iron, copper, manganese, selenium.
Have a protective effect when exposed to mercury on the human body. zinc and especially, selenium. It is believed that the protective effect of selenium is due to the demethylation of mercury and the formation of a non-toxic compound, the selenium-mercury complex.
The high toxicity of mercury is also evidenced by very low MPC values: 0.0003 mg/m 3 in air and 0.0005 mg/l in water. A safe level of mercury in the blood is considered to be 50-100 mcg/l. A person receives about 0.05 mg of mercury in their daily diet, which corresponds to FAO/WHO recommendations.
Mercury enters the human body to the greatest extent with fish products, in which its content can be many times higher than the maximum permissible concentration. Fish meat has the highest concentration of mercury and its compounds, since it actively accumulates them from water and food, which includes various hydrobionts rich in mercury. For example, predatory freshwater fish may contain from 107 to 509 μg/kg, non-predatory freshwater fish from 78 to 200 μg/kg, and ocean non-predatory fish from 300 to 600 μg/kg Hg.
The fish body is capable of synthesizing methylmercury, which accumulates in the liver. Some fish species have a protein in their muscles, metallothionein, which forms complex compounds with various metals, including mercury, thereby promoting the accumulation of mercury in the body and its transmission through food chains. In such fish, mercury levels reach very high concentrations: sabrefish contain from 500 to 20,000 μg/kg, and Pacific marlin from 5,000 to 14,000 μg/kg. Other products have the following mercury content (µg/kg).
In animal products: meat 6-20, liver 20-35, kidneys 20-70, milk 2-12, butter 2-5, eggs 2-15; in edible parts of agricultural plants: vegetables 3-59, fruits 10-124, legumes 8-16, grains 10-103; in cap mushrooms 6-447, in overripe ones up to 2000 μg/kg, and, unlike plants, methylmercury can be synthesized in mushrooms. When cooking fish and meat, the concentration of mercury in them decreases, but with similar processing of mushrooms it remains unchanged. This difference is explained by the fact that in mushrooms mercury is associated with the amino groups of nitrogen-containing compounds, in fish and meat - with sulfur-containing amino acids.
Lead - one of the most common and dangerous toxicants. The history of its use is very ancient, which is due to the relative ease of its production and its high prevalence in the earth’s crust (1.6x10 -3%). Lead compounds - Pb 3 O 4 and PbSO 4 - are the basis of widely used pigments: red lead and lead white. Glazes that are used to coat ceramic ware also contain Pb compounds.
Metal lead has been used in the laying of water pipes since the times of Ancient Rome. Currently, the list of areas of its application is very wide: the production of batteries, electrical cables, chemical engineering, the nuclear industry, the production of enamels, putties, varnishes, crystal, pyrotechnic products, matches, plastics, etc.
World lead production is more than 3.5x10 6 tons per year. As a result of human production activities, 500-600 thousand tons enter natural waters annually, and about 450 thousand tons are released into the atmosphere in a processed and finely dispersed state, the vast majority of which settles on the surface of the Earth. The main source of lead air pollution is vehicle exhaust gases (260 thousand tons) and coal combustion (about 30 thousand tons).
In countries where the use of gasoline with added tetraethyl lead reduced to a minimum, the lead content in the air was reduced many times over. It should be emphasized that many plants accumulate lead, which is transmitted through food chains and is found in the meat and milk of farm animals; especially active accumulation of lead occurs near industrial centers and major highways.
The daily intake of lead into the human body with food is 0.1-0.5 mg, with water - 0.02 mg. The lead content (in mg/kg) in various products is as follows: fruits 0.01-0.6; vegetables 0.02-1.6; cereals 0.03-3.0; bakery products 0.03-0.82; meat and fish 0.01-0.78; milk 0.01-0.1. The human body absorbs an average of 10% of incoming lead, and children absorb 30-40%. From the blood, lead enters soft tissues and bones, where it is deposited in the form of triphosphate.
The mechanism of the toxic effect of lead is twofold. Firstly, blockade of functional SH groups of proteins and, as a consequence, inactivation of enzymes; secondly, the penetration of lead into nerve and muscle cells, the formation of lead lactate, then lead phosphate, which create a cellular barrier to the penetration of Ca 2+ ions. The main targets of lead exposure are the hematopoietic, nervous and digestive systems, as well as the kidneys.
Lead intoxication can lead to serious health problems, manifested in frequent headaches, dizziness, increased fatigue, irritability, poor sleep, muscle hypotonia, and in the most severe cases to paralysis and paresis, mental retardation. Poor nutrition, deficiency in the diet of calcium, phosphorus, iron, pectins, proteins (or increased intake of calciferol) increase the absorption of lead, and therefore its toxicity. The acceptable daily intake (ADI) of lead is 0.007 mg/kg; MPC value in drinking water is 0.05 mg/l.
Measures to prevent lead contamination of raw materials and food products should include state and departmental control over industrial emissions of lead into the atmosphere, water bodies and soil. It is necessary to significantly reduce or completely eliminate the use of tetraethyl lead in gasoline, lead stabilizers, polyvinyl chloride products, dyes, packaging materials, etc.
Cadmium Widely used in various industries. Cadmium enters the air together with lead during fuel combustion at thermal power plants and with gas emissions from enterprises producing or using cadmium. Soil contamination with cadmium occurs when cadmium aerosols settle from the air and is supplemented by the application of mineral fertilizers: superphosphate (7.2 mg/kg), potassium phosphate (4.7 mg/kg), saltpeter (0.7 mg/kg).
The content of cadmium is also noticeable in manure, where it is detected as a result of the following chain of transitions: air - soil - plants - herbivores - manure. In some countries, cadmium salts are used as antiseptic and anthelmintic drugs in veterinary medicine. All this determines the main routes of cadmium contamination of the environment, and, consequently, food raw materials and food products.
The cadmium content (in µg/kg) in various products is as follows. Plant products: grains 28-95, peas 15-19, beans 5-12, potatoes 12-50, cabbage 2-26, tomatoes 10-30, lettuce 17-23, fruits 9-42, vegetable oil 10-50, sugar 5-31, mushrooms 100-500; in livestock products: milk - 2.4, cottage cheese - 6.0, eggs 23-250. It has been established that approximately 80% of cadmium enters the human body through food, 20% through the lungs from the atmosphere and through smoking. With the diet, an adult receives up to 150 mcg/kg or more of cadmium per day.
One cigarette contains 1.5-2.0 μg of Cd. Like mercury and lead, cadmium is not an essential metal. Once in the body, cadmium exhibits a strong toxic effect, the main target of which is the kidneys. The mechanism of the toxic effect of cadmium is associated with the blockade of sulfhydryl groups of proteins; in addition, it is an antagonist of zinc, cobalt, selenium, and inhibits the activity of enzymes containing these metals. Cadmium is known to disrupt the metabolism of iron and calcium.
All this can lead to a wide range of diseases: hypertension, anemia, coronary heart disease, renal failure and others. Carcinogenic, mutagenic and teratogenic effects of cadmium have been noted. According to WHO recommendations, the permissible daily intake (ADI) of cadmium is 1 mcg/kg body weight.
Of great importance in the prevention of cadmium intoxication is proper nutrition (inclusion in the diet of proteins rich in sulfur-containing amino acids, ascorbic acid, iron, zinc, selenium, calcium), control of cadmium content (polarographic, atomic absorption analyzes) and exclusion from the diet of foods rich in cadmium. cadmium
Aluminum. The first data on the toxicity of aluminum were obtained in the 70s. XX century, and this came as a surprise to humanity. Being the third most abundant element in the earth's crust (8.8% of the mass of the earth's crust is A1) and possessing valuable qualities, metallic aluminum has found wide application in technology and everyday life. Suppliers of aluminum to the human body are aluminum cookware if it comes into contact with an acidic or alkaline environment, and water, which is enriched with A1 3+ ions when it is treated with aluminum sulfate at water treatment plants.
Acid rain also plays a significant role in environmental pollution with A1 3+ ions. You should not abuse medications containing aluminum hydroxide: antihemorrhoids, antiarthritics, and those that reduce the acidity of gastric juice. Aluminum hydroxide is added as a buffer additive to some aspirin preparations and lipstick. Among food products, tea has the highest concentration of aluminum (up to 20 mg/g).
A1 3+ ions entering the human body in the form of insoluble phosphate are excreted in feces, partially absorbed into the blood and excreted by the kidneys. When kidney function is impaired, aluminum accumulates, which leads to impaired metabolism Ca, Mg, P, F, accompanied by an increase in bone fragility and the development of various forms of anemia. In addition, more formidable manifestations of aluminum toxicity were discovered: speech impairment, memory loss, disorientation, etc. All this makes it possible to bring “harmless” aluminum, considered non-toxic until recently, closer to the “dark trio” of supertoxicants: Hg, Pb , Cd.
Arsenic As an element in its pure form, it is poisonous only in high concentrations. It belongs to those trace elements whose necessity for the functioning of the human body has not been proven, and its compounds, such as arsenic anhydride, arsenites and arsenates, are highly toxic. Arsenic is contained in all objects of the biosphere (in the earth's crust - 2 mg/kg, in sea water - 5 μg/kg). Known sources of environmental pollution with arsenic are power plants using brown coal, copper smelters; it is used in the production of semiconductors, glass, dyes, insecticides, fungicides, etc.
The normal level of arsenic in food should not exceed 1 mg/kg. For example, the background arsenic content (mg/kg): in vegetables and fruits 0.01-0.2; in cereals 0.006-1.2; in beef 0.005-0.05; in the liver 2.0; eggs 0.003-0.03; in cow's milk 0.005-0.01. Increased levels of arsenic are observed in fish and other aquatic organisms, in particular in crustaceans and mollusks. According to FAO/WHO, an average of 0.05-0.45 mg of arsenic enters the human body in the daily diet. DDI - 0.05 mg/kg body weight.
Depending on the dose, arsenic can cause acute and chronic poisoning; a single dose of 30 mg of arsenic is fatal to humans. The mechanism of the toxic effect of arsenic is associated with blocking the SH groups of proteins and enzymes that perform a wide variety of functions in the body.
2013, the Unified State Exam in English begins. I read the first task and don’t understand what I want more - to laugh or be indignant. I saw the phrase “Kate is thinking about a present for her former school friend” two days ago in the Snob article about the mass leak of exam assignments. Tasks identical to real ones were posted on the Internet for at least three days. In the Russian language - a few hours, in literature - about a week. As a result, there were 10 thousand 100-point students in the country (according to data from the official Unified State Exam portal), in 2012 there were 3,571 people.
Happy schoolchildren achieved good results in top universities. On average, tests seen in advance raised an applicant's score by twenty points. Educational institutions like Moscow State University tried to fight back with the help of additional exams. But this did not help too much, because enrollment is based on the sum of all tests.
It cannot be said that last year’s leaks led to the fact that only illiterate people entered universities. To write off correctly also requires intelligence, and universities had the opportunity to restore justice at the very first session. But faith in the state's ability to fight corruption has been undermined.
Unified State Exam on Garlic
What about this year? Rosobrnadzor swears that they managed to defeat the plums. Indeed, not a single message on the topic “Answers were posted on the Internet again,” but as many as “In region N they were kicked out for cheating.” The first reaction is in the best traditions of Stanislavsky: “I don’t believe it.” I write to applicants I know: “Was there a leak?” Eleventh graders from different parts of the country swear in unison that nothing happened:
- As far as I know, no one has found the correct KIMs or answers, certainly not among my friends. Although there were spurs,” admits graduate Alena.
I still don't believe it. I'm looking for assignments myself. After five minutes of searching VKontakte, the following dialogue begins:
- Timur, hello! Interested in answers to the Unified State Exam (reserve dates) in Russian and mathematics. What is the price of the issue and how to transfer the money? Very, very necessary!
— Three hundred rubles answers + KIMs. One item. The total will be 600 rubles for two items...
There are many such advertisements, no one removes them. The only thing that confuses me is the price. Last year, in some cases, tens of thousands were asked. I'm starting to believe the officials.
“It definitely wasn’t like in 2013.” I work with schoolchildren, information from them. Two months before the Unified State Exam, people began to appear around schools telling children: “Now you give us 1,500 rubles, we will give you the answers a day before the exam.” Classes chipped in. But no one seems to have gotten the right answers. They monitored the Internet as best they could and did not give tasks to the children of their friends. This cannot be proven, but there is a small group of schoolchildren who must write only their name on a form and they will be given the required points. I think all the machinations came down to this,” Irina Maslyakova, senior lecturer at the Department of Higher Mathematics of the Russian Economic University. Plekhanov, confirms my opinion.
“This year the control was much more serious. There are fewer people interested in high scores: Unified State Examination results were excluded from the performance indicators of governors. They didn’t catch everyone, but they showed with examples that it won’t be possible to do this with impunity,” adds Yuri Romanov, senior lecturer at the Faculty of History at Moscow State Pedagogical University.
When it wants, our state knows how to work and stop violations. Everything was foreseen, everything worked as it should, admission to universities this summer will be fair. But then, in the depths of my consciousness, the nasty “I don’t believe it” arose again.
Echo of last year
“Admission to organizations carrying out educational activities in bachelor’s and specialist’s programs is allowed based on the results of the Unified State Examination, issued in 2012 and 2013 and valid until the end of 2016 and 2017, respectively” - a document with this text appeared on the Rosobrnadzor website.
Exam results are now valid for four years. That is, it turns out that a student who cheated last year will be able to enter a more prestigious university this year. Current eleventh graders will have lower scores.
— This was voiced by the Minister of Education himself. They don't know what to do with it. For now they just lowered the requirements. There were so many bad marks in Russian that we had to greatly reduce the passing score,” comments Irina Maslyakova.
That is, the Unified State Exam was conducted relatively honestly, but the effect of last year will be felt for several more years. I really want to believe that over time the security measures will yield results. I really feel sorry for the schoolchildren. They will have to finally get used to psychological pressure, searches at the entrance to the office and video cameras around.
Could you pass the Unified State Exam?
Options from the demo version of FIPI for 2014 are given (the simplest tasks were selected)
Russian language
In which row is the same letter missing in all words?
- By...laying, o...cutting, on...lowercase.
- Pr...stand up, pr...glue, pr...school.
- To...get into, over...investment, out...of.
- Bar...barry, s...sarcastically, monkey...yana.
Biology
The gender of the unborn child is determined by:
- fusion of gametes;
- maturation of gametes;
- fragmentation of blastomeres;
- organ formation.
Geography
Which of the following countries has the largest proportion of people over 65 years of age in the population's age structure?
- Brazil.
- Algeria.
- Bangladesh.
- Norway.
Mathematics
There are only 25 tickets in the collection of biology tickets, two of them contain a question about mushrooms. At the exam, the student receives one randomly selected ticket from this collection. Find
the likelihood is that there will be no question about mushrooms on this ticket.
Story
Which of the following can be attributed to the results of industrialization of the USSR in the pre-war period?
- Creation of a complex of heavy industry enterprises.
- Reducing military spending.
- Intensive development of light industry.
- Formation of a multi-structure economy.
Physics
Gas particles are on average at such distances from each other that the attractive forces between them are insignificant. This explains:
- high speed of gas particles;
- value of the speed of sound in gas;
- propagation of sound waves in gas;
- the ability of gases to expand without limit.
Chemistry
For the human body, each of the two ions is most toxic:
- K+ and Pb2+
- Na+ and Cu2+
- Cu2+ and Hg2+
- Ca2+ and Hg2+
Right answers
Russian language - 2, biology - 1, geography - 4, mathematics - 0.92, history - 1, physics - 4, chemistry - 3.
Preview:
Test No. 1
Structure of matter
1 option | Option 2 |
SiO 2, K 3 N, O 2, C 4 H 10. 2) Give characteristics of the substance whose formula CH 2 = C (CH 3 ) − C (CH 3 ) = CH 2 according to plan: A) name, class; B) types of isomerism; CaCO 3 →CaO→Ca(OH) 2 →Ca(NO 3) 2 →CaSiO 3 Name the reaction products. 4) Zinc was added to a solution of hydrochloric acid with a volume of 120 ml with a mass fraction of 15% and a density of 1.07 g/ml. Determine the volume of hydrogen (no.) that will be released as a result of the reaction. | 1) Determine the type of chemical bond in substances whose formulas are: N 2, PH 3, Na 2 O, C 2 H 4. Write their structural formulas. 2) Give a description of a substance whose formula is CH≡C−C(CH 3) 2 −CH 3 according to plan: A) name, class; B) hybridization of all carbon atoms; B) types of isomerism; D) make 1 isomer and 1 homologue and give them a name. 3) Write the reaction equations with which you can carry out the following transformations: СuO→Cu→CuCl 2 →Cu(OH) 2 →CuSO 4 Name the reaction products. 4) Calculate the volume of ammonia, measured at ambient conditions, that will be required to completely neutralize a 20 ml solution of sulfuric acid with a mass fraction of 3%, density 1.02 g/ml. |
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Test No. 2
Chemical reactions
1 option
PART A | PART B AND C |
A 1. Indicate the correct characteristics of the reaction C + O 2 = CO 2 + Q a) connection, ORR, exothermic, reversible; b) exchange, ORR is not, irreversible, endothermic; c) connection, ORR, exothermic, irreversible; d) connection, ORR is not, endothermic, irreversible. A 2. Specify the hydrogenation reaction: a) interaction of ethene with water; b) synthesis of propane from propene; c) synthesis of ethene from ethanol; d) synthesis of polyethylene. A 3. Reaction occurring at the phase interface: A 4. From increasing the surface area of contact of substances does not depend reaction rate between: a) S and Al; b) H 2 and Cl 2; c) Al and Cl 2; d) Mg and HCl. A 5. Equilibrium in the CaCO reaction 3 ↔ CaO + CO 2 – Q shifts to the right when: a) ↓t, p; b) t, ↓p; c) t, p; d) ↓t, ↓p. A 6. Reactions whose equation is S + 6HNO 3 =H 2 SO 4 + 6NO 2 + 2H 2 O corresponds to the scheme of changes in the degree of oxidation of nitrogen a) N +4 → N +5; b) N +5 → N +4; c) N 0 → N +4; d) N +3 → N -3. A 7. Only hydroxide ions as anions are formed during dissociation: A) MgOHCl; b) NaOH; c) HONO 2 ; d) HCOOH. A 8. Dissociation in three stages is possible in solution: a) aluminum chloride; b) potassium orthophosphate; c) aluminum nitrate; d) orthophosphoric acid. A 9. Abbreviated ionic equation for the Ba reaction 2+ + SO 4 2- = BaSO 4 a) Ba + H 2 SO 4; b) BaO + HCl; c) BaO + H 2 SO 4; d) BaCl 2 + H 2 SO 4; A 10. The solution has an acidic reaction: a) Na 2 SO 4; b) CaCO 3; c) AlCl 3; d) NaCl. | IN 1. In the above diagram, HNO 3 + P + H 2 O → NO + H 3 PO 4 AT 2. a) aluminum sulfate; 1) does not undergo hydrolysis; b) potassium sulfite; 2) hydrolysis at the cation; c) sodium phenolate; 3) hydrolysis by anion; d) barium nitrate. 4) hydrolysis by cation and anion From 1. Iron weighing 11.2 g was dissolved in 300 ml of hydrochloric acid solution with a density of 1.05 g/ml with a mass fraction of 10%. Calculate the mass fraction of ferric chloride (2) in the resulting solution. |
Test No. 2
Chemical reactions
Option 2
PART A | PART B AND C |
A 1. Specify the correct characteristics of the 2H reaction 2 O↔ 2H 2 + O 2 -Q a) connection, ORR, endothermic, reversible; b) decomposition, ORR, endothermic, reversible; c) decomposition, ORR, exothermic, reversible; d) decomposition, ORR is not, endothermic, irreversible. A 2. Specify the dehydration reaction: a) interaction of ethene with water; b) obtaining butene-2 from butanol-2; c) ammonia synthesis; d) protein hydrolysis. A 3. Reaction occurring in a homogeneous medium: a) catalytic; b) homogeneous; c) heterogeneous; d) OVR. A 4. To increase the rate of a chemical reaction Zn + 2H + = Zn 2+ + H 2 + Q is necessary: a) ↓ C (H + ) ; b) C (H + ) ; c) ↓ t; d) r. A 5. To shift the chemical equilibrium in the system Fe 3 O 4 (t.) + CO (g.) ↔ 3FeO (t.) + CO 2 (g.) - Q does not affect: a) ↓С (СО); b)↓С (СО2); c) t; d) r. A 6. Chlorine in the reaction 2KBr + Cl 2 = Br 2 + 2KCl a) is a reducing agent; b) does not change the oxidation state; c) is an oxidizing agent; d) oxidizes. A 7. Chloride ions are formed upon dissociation in an aqueous solution: A) KClO 3; b) CCl 4; c) NaClO; d) CuOHCl. A 8. Electrolytes include each of two substances: a) NaOH, CH 3 COONa; b) Fe 2 O 3, CH 3 COOH; c) BaCl 2, C 2 H 5 OH; d) C 6 H 12 O 6, CaCO 3. A 9. Abbreviated ionic equation of Fe 2+ + 2OH - = Fe(OH) 2 ↓ corresponds to the interaction: a) Fe(NO 3 ) 3 + KOH; b) Na 2 S + Fe(NO 3 ) 2; c) FeSO 4 + LiOH; d) Ba(OH) 2 + FeCl 3; A 10. The solution has an alkaline reaction: a) MgSO 4; b) KI; c) AlCl 3; d) Na 2 SO 3. | IN 1. In the above diagram H 2 S + Cl 2 + H 2 O → HCl + H 2 SO 4 Determine the oxidation state of each element and arrange the coefficients using the electronic balance method. AT 2. Match the name of the salt with its ability to hydrolyze. NAME OF SALT HYDROLYSIS ABILITY a) chromium sulfide (3); 1) hydrolyzes at the cation; b) aluminum chloride; 2) hydrolyzes at the anion; c) potassium sulfate; 3) hydrolyzes at the cation and anion; d) sodium phosphate. 4) does not hydrolyze. From 1. Aluminum carbide was dissolved in 250 g of 20% sulfuric acid solution. The methane released in this case took up a volume of 4.48 liters (n.s.). Calculate the mass fraction of sulfuric acid in the resulting solution. |
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Test No. 3
Substances and their properties
1 option
Part A | Part B and C |
A1. General formula of oxides: a) E x O y ; b) M(OH)n; c) N x Ko; d) M x (Ko)y. A2. General formula of saturated monohydric alcohols: a) NH 3; b) PH 3; c) AsH 3; d) SbH 3 . a) CH 3 COOH; b) C 2 H 5 COOH; c) C 15 H 31 COOH; d) HCOOH. A5. Ionic reaction equation H+ + OH - = H 2 O corresponds to the interaction: a) potassium hydroxide and nitric acid; b) barium hydroxide and sulfuric acid; c) lithium hydroxide and barium chloride; d) ammonia and hydrobromic acid. A6. Ethylamine can be obtained by reacting: a) ethane with nitric acid; b) ethane with potassium permanganate solution; c) ethin with water; d) nitroethane with hydrogen. A7. Beryllium hydroxide interacts with the substance: a) NaCl; b) NO; c) H 2 O; d) KOH. A8. Formulas of interaction products conc. H 2 SO 4 with silver: a) H 2 and Ag 2 SO 4; b) SO 2, H 2 O and Ag 2 SO 4; c) H 2 S, H 2 O and Ag 2 SO 4 ; d) the reaction does not occur. A9. In the chain of transformations C 2 H 4 →X→CH 3 COH substance X is: a) C 2 H 6; b) C 2 H 5 OH; c) CH 3 COOH; d) CH 3 OH. A10. Indicate the transformation consisting of 1 stage: a) C 2 H 6 → C 2 H 5 OH; b) CH 4 →C 6 H 6; | c) FeCl 2 →Fe(OH) 3; d) CuO→Cu. IN 1. Match: AT 2. Which of the proposed substances: magnesium, nitric acid, oxygen, calcium hydroxide will react with: a) hydrochloric acid; b) methylamine? Write down the corresponding reaction equations. |
Test No. 3
Substances and their properties
Option 2
Part A | Part B and C |
C1. How many grams of salt are obtained when a solution of sodium hydroxide weighing 10 g reacts with a solution of nitric acid weighing 18.9 g? A1. General formula of bases: a) E x O y ; b) M(OH)n; c) N x Ko; d) M x (Ko)y A2. General formula of saturated monobasic carboxylic acids: a) R – OH; b) R – NH 2; c) RCOOH; d) NH 2 – R – COOH. A3. The main properties are most clearly expressed in the substance, the formula of which is: a) CH 3 NH 2; b) C 2 H 5 NH 2; c) C 6 H 5 NH 2; d) (C 6 H 5 ) 2 NH 2 . A4. Acidic properties are most pronounced in a substance whose formula is: a) HNO 2; b) HPO 3; c) HAsO 3; d) HNO 3. A5. Ionic equation for the reaction CO 3 2- + 2H + = H 2 O + CO 2 corresponds to the interaction: a) sodium carbonate and acetic acid; b) calcium carbonate and nitric acid; c) calcium bicarbonate and hydrochloric acid; d) barium carbonate and formic acid. A6. Chromium(III) hydroxide can be obtained by reacting: a) chromium chloride (3) with calcium hydroxide; b) chromium nitrate (3) with copper hydroxide (2); c) chromium oxide (3) with sulfuric acid; d) chromium oxide (2) with hydrochloric acid. A7. Aminoacetic acid interacts with the substance: a) CO 2; b) KNO 3; c) H 2; d) HCl. 3 with zinc: a) H 2 and Zn(NO 3) 2; b) NO 2, H 2, Zn(NO 3) 2; c) NO, H 2 O, Zn(NO 3 ) 2 ; d) the reaction does not occur. A9. In the chain of transformations CH 3 COH→X→CH 3 COOC 2 H 5 substance X is: a) C 2 H 6 (OH) 2; b) C 3 H 7 COOH; c) CH 3 OH; d) CH 3 COOH. A10. Specify a transformation consisting of 2 stages: a) C 2 H 6 → C 4 H 10; b) CH 4 →CH 3 Cl; c) Cu→CuCl 2; d) C 3 H 8 →C 3 H 7 NO 2 | c) FeCl 2 →Fe(OH) 3; d) CuO→Cu. AT 2. Which of the proposed substances: calcium, sulfuric acid, carbon dioxide, sodium carbonate will react with: a) barium hydroxide; b) acetic acid? Write down the corresponding reaction equations. C1. How many grams of salt are obtained when a solution of sodium hydroxide weighing 4 g reacts with a solution of hydrochloric acid weighing 18.25 g? |
Preview:
Test in chemistry for grade 11 (profile) on the topics: “Structure of the atom”, “Chemical bond”
Explanatory note
The test was compiled for 11th grade students (profile) and is designed to last 45 minutes. The work consists of three parts: part A – tasks of a basic level of complexity; Part B – tasks of an increased level of complexity; Part C – tasks of a high level of complexity. Part A contains 10 tasks with multiple choice of the correct answer. Each task is worth 1 point. Part B consists of two tasks worth 2 points. Part C includes one task worth 4 points.
The text of the test was developed on the basis of thematic tests by V.N. Doronkin and textbook D.Yu. Dobrotina “Chemistry. Grade 11. Tests in a new format."
Objectives of the test:
1) Monitor the knowledge of 11th grade students on the topics: “Atomic structure”, “Chemical bond”.
2) Continue preparing students for the Unified State Exam in chemistry.
Requirements (skills) tested by job tasks:
1) Determine the number of electrons in the external level and the number of energy levels in atoms of chemical elements.
2) Identify an atom or ion using its electronic formula.
3) Apply knowledge about the patterns of changes in the properties of atoms, simple substances and compounds formed by chemical elements within the main subgroups and periods of the Periodic System D.I. Mendeleev.
4) Distinguish the types of chemical bonds from each other.
5) Determine the type of crystal lattice.
6) Know the features of substances of molecular and non-molecular structure.
7) Write down the formulas of higher oxides and hydroxides.
8) Draw up electronic graphic formulas of atoms of chemical elements.
1 option
Part A | Parts B and C |
A1. The number of energy layers and the number of electrons in the outer energy layer of the selenium atom are equal, respectively: a) 4, 6; b) 3, 6; c) 4, 7; d) 3, 7. A2. Electronic formula 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 has an element atom: a) Va; b) Mg; c) Ca; d) Sr. A3. Chemical elements are arranged in increasing order of their atomic radii in the series: a) Zn, Cd, Ca; b) Br, Cl, F; c) In, Sn, Sb; d) Br, Se, As. A4. Higher oxide composition E 2 O 3 form all the elements: a) ΙΙΙA group; b) ΙVA groups; c) VΙA group; d) VΙΙA groups. A5. In the HCl molecule the chemical bond is: A6. Compounds with covalent nonpolar and ionic bonds are, respectively: a) N 2 and O 3; b) N 2 and NO; c) N 2 and NaCl; d) N 2 and CaSO 4. A7. The number of σ bonds in an ethyne molecule is: a) 5; b) 4; at 3; d) 6. A8. Each of two substances has an ionic crystal lattice: a) NaCl, H 2 S; b) KF, H 2 O; c) HNO 3, Cs 2 S; d) Na 2 CO 3, K 2 S. A9. Iodine has a crystal lattice: a) ionic; b) atomic; c) molecular; d) metal. A10. Non-molecular structure has: a) fullerene; b) crystalline sulfur; c) carbon dioxide; d) diamond. | IN 1. AT 2. An increase in the basic properties of higher hydroxides occurs in the ranks of their constituent elements: 1) Na → Mg → Al; 2) As → P → N; 3) P → S → Cl; 4) B → Be → Li; 5) Mg → Ca → Ba. C1. Write an electron graphic formula for the sulfur atom in the ground state. Write down the formulas of higher sulfur oxide and hydroxide; what properties do these compounds have? Determine the type of chemical bond in these compounds. |
Test in chemistry for grade 11 (profile)
The structure of the atom. Chemical bond
Option 2
Part A | Parts B and C |
A1. The number of energy layers and the number of electrons in the outer energy layer of the iron atom are equal, respectively: a) 4, 2; b) 4, 8; c) 4, 6; d) 4, 1. A2. Electronic formula 1s 2 2s 2 2p 6 3s 2 3p 6 corresponds to the particle: a) Li + ; b) K + ; c) Cs + ; d) Na+. A3 . Chemical elements are arranged in decreasing order of their atomic radii in the series: a) Ba, Cd, Ra; b) In, Pb, Sb; c) Cs, Na, H; d) Br, Se, As. A4 . Higher oxide composition EO 2 form all the elements: a) ΙVA groups; b) ΙΙA group; c) 4 periods; d) 2 periods. A5. In a CO 2 molecule chemical bond: a) ionic; b) covalent polar; A6. c) covalent nonpolar; d) hydrogen. Compounds with covalent polar and covalent nonpolar bonds are, respectively: a) I 2 and H 2 Te; b) HBr and N 2; c) Fe and HF; d) CO and SO 2. A7. The number of π bonds in an ethene molecule is: A8. a) 1; b) 4; at 2; d) 3. Each of the compounds has a molecular structure: a) H 2 O, K 2 SO 4; b) C 6 H 12 O 6, NH 3; c) HCl, KNO 3; d) BaO, Na 2 CO 3. A9. a) atomic; b) ionic; c) metal; d) molecular. A10. The oxide has an ionic structure: a) silicon; b) cesium; c) carbon (ΙV); d) nitrogen (ΙV). | IN 1.Establish a correspondence between the formula of a substance and the type of chemical bond in it. B2.An increase in the acidic properties of higher hydroxides occurs in the series of their constituent elements: 1) Al → Si → P; 2) S → Se → Te; 3) Cl → Br → I; 4) B → C → N; 5) Mg → Ca → Sr. C1.Make an electron graphic formula for the calcium atom in the ground state. Write down the formulas of higher calcium oxide and calcium hydroxide; what properties do these compounds have? Determine the type of chemical bond in these compounds. |
Preview:
1 option
Part A.
A1. Particles contain the same number of electrons:
1) Al3+ and N3-
2) Ca2+ and Cl5+
3) S0 and Cl-
4) N3- and P3-
A2. Chemical bond in methane and calcium chloride respectively
1) covalent polar and metallic;
2) ionic and covalent polar;
3) covalent nonpolar and ionic;
4) covalent polar and ionic.
A3. The molecular structure has
1) silicon(IV) oxide;
2) barium nitrate;
3) sodium chloride;
4) carbon monoxide (II).
A4.Zinc reacts with solution
1) copper(II) sulfate;
2) potassium chloride;
3) sodium sulfate;
4) calcium nitrate.
A5. Aluminum hydroxide reacts with each of two substances:
1) KOH and Na2 SO4 ;
2) HCl and NaOH;
3) CuO and KNO3 ;
4) Fe2 O3 and HNO3 .
A6. In the transformation scheme: Fe →X1FeCl3 → X2Fe(OH)3 substances X1 and X2 are respectively
1) Cl2 and Cu(OH)2 ;
2) CuCl2 (solution) and NaOH(solution);
3)Cl2 and NaOH(solution);
4) HCl and H2 O.
A7. Cis- and trans-isomerism is characteristic of:
1) butene-1; 2) butene-2;
3) butina-1; 4) butina-2.
A8. Will react with both nitric acid and copper hydroxide (2)
1) phenol;
2) glycerin;
3) ethanol;
4) methyl acetate.
Part B.
IN 1. Establish a correspondence between the class of inorganic substances and the chemical formula of the substance.
Class of inorganic substances | Chemical formula |
A) basic oxide; B) acid oxide; B) amphoteric oxide; D) acid. | 1)B2 O3 ; 2) BaO; 3) H3 P.O.3 ; 4) ZnO; 5) Zn(OH)2 ; 6)Na2 ZnO2 . |
AT 2. Establish a correspondence between the formula of the salt and the product formed at the cathode during the electrolysis of its aqueous solution.
AT 4. Establish a correspondence between the formula of a substance and the reagents with each of which it can interact.
Substance formula | Reagents |
A) HCl; B) K2 SiO3 ; B) Na2 CO3 ; D) CuCl2 . | 1) Ag, H3 P.O.4 , MgCl2 ; 2) H2 SO4 , HCl, CaCl2 ; 3) NaOH, Fe, Na2 S; 4) H2 SO4 , NaOH, CuO; 5) AgCl, SiO2 , H2 |
Part C.
Na2 SO3 + … + KOH → K2 MnO4 + … + H2 O
C2. Determine the mass fractions (in %) of iron(II) sulfate and aluminum sulfide in the mixture if, when treating 25 g of this mixture with water, a gas was released that completely reacted with 960 g of a 5% solution of copper sulfate.
Final testing for the 11th grade profile course
Option 2
Part A.
A1. In the series of elements Na→ Mg→ Al→ Si
1) atomic radii decrease;
2) the number of protons in the nuclei of atoms decreases;
3) the number of electronic layers in atoms increases;
4) the highest oxidation state of atoms decreases.
A2. Chlorine has an oxidation state of +7 in the compound:
1) Ca(ClO2 ) 2 ;
2) HClO3 ;
3) NH4 Cl;
4) HClO4 .
A3. Which of the following oxides reacts with a solution of hydrochloric acid, but does not react with a solution of sodium hydroxide?
1) CO;
2) SO3 ;
3) ZnO;
4) MgO.
A4. Barium carbonate reacts with a solution of each of two substances:
1) H2 SO4 and NaOH;
2) NaCl and CuSO4 ;
3) HCl and CH3 COOH;
4) NaHCO3 and HNO3 .
A5. The largest amount of sulfate ions is formed in solution during dissociation of 1 mol:
1) sodium sulfate;
2) copper(II) sulfate;
3) aluminum sulfate;
4) magnesium sulfate.
A6. Abbreviated ionic equation H+ + HE- = N2 O corresponds to interaction
1) H2 SO4 with NaOH;
2) Cu(OH)2 with HCl;
3) NH4 Cl with KOH;
4) HCl with HNO3 .
A7. For the human body, each of the two ions is most toxic:
1) K+ and Pb2+
2)Na+ and Cu2+
3) Cu2+ and Hg2+
4) Ca2+ and Hg2+ .
A8. The rate of reaction of nitrogen with hydrogen will decrease when:
1) decrease in temperature;
2) increasing nitrogen concentration;
3) use of a catalyst;
4) increasing pressure in the system.
Part B.
IN 1. Match the name of a substance with the class of inorganic compounds to which it belongs.
AT 2. Establish a correspondence between the formula of the salt and the product formed on the inert anode during the electrolysis of its aqueous solution.
Salt formula | Products on the anode |
A) Rb2 SO4 ; B) CH3 COOK; B) BaBr2 ; D) CuSO4. | 1) methane; 2) sulfur dioxide; 3) oxygen; 4) hydrogen; 5) bromine; 6) ethane and carbon dioxide. |
B3. Match the name of the salt with its relationship to hydrolysis.
AT 4. Match the reactants with the reaction products.
Reacting substances | Reaction products |
A) Al and KOH (solution); B) Al and H2 SO4 (div.); B) Al2 S3 and H2 O; D) Al and H2 O | 1) aluminum hydroxide and sulfur; 2) aluminum hydroxide and hydrogen sulfide; 3) potassium tetrahydroxyaluminate and hydrogen; 4) aluminum sulfate and hydrogen; 5) potassium aluminate and aluminum oxide; 6) aluminum hydroxide and hydrogen. |
Part C.
C1. Using the electron balance method, create an equation for the reaction
FeSO4 + KClO3 + … → K2 FeO4 + … + K2 SO4 + …
Identify the oxidizing agent and the reducing agent.
C2. Aluminum carbide was dissolved in a 15% solution of sulfuric acid weighing 300 g. The methane released in this case occupied a volume of 2.24 liters (n.s.). Calculate the mass fraction of sulfuric acid in the resulting solution.
A1. The particle has the electronic configuration of the argon atom:
A2. In the series of chemical elements Na→Mg→Al→Si
1) the number of valence electrons in atoms increases
2) the number of electronic layers in atoms decreases
3) the number of protons in the nuclei of atoms decreases
4) atomic radii increase
A3. Are the following statements about metals true?
A. Metals of group IIA form higher oxides of the composition R 2 O.
B. Metallic properties increase in the series Na→K→Rb.
1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect
A4. Due to the shared electron pair, a chemical bond is formed in the compound
A5. The oxidation state of oxygen in the BaO 2 compound is equal to
A6. Has a molecular crystal lattice
1) quicklime
2) dimethyl ether
4) pyrolusite
A7. Among the listed substances:
oxides include:
1) HGE 2) ABC 3) ABE 4) WHERE
A8. Are the following statements about the chemical properties of chlorine correct?
A. Many dyes become discolored in chlorine water.
B. Chlorine can react with potassium bromide.
1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect
A9. Alkali is formed when dissolved in water
1) chlorine oxide (I)
2) chromium (VI) oxide
3) barium oxide
4) magnesium oxide
A10. Hydrogen is not released in the reaction of zinc with
1) nitric acid
2) sodium hydroxide
3) hydrochloric acid
4) sulfuric acid
A11. Calcium bicarbonate is formed from calcium carbonate when exposed to
1) excess hydrochloric acid
2) aqueous solution of KHCO 3
3) aqueous solution of CO 2
4) hydrogen
A12. In the NaNaH transformation scheme 
NaOH
Substances X 1 and X 2 are respectively
A13. Only ϭ bonds are present in the molecule
1) propionic acid
2) ethylene
4) cyclobutane
A14. Both hexane and toluene react with
1) bromine water
2) potassium permanganate solution
4) hydrogen
A15. Ethylene glycol interacts with
2) nitric acid
3) iron (II) oxide
A16. As an aldehyde and as an alcohol, glucose interacts with a substance whose formula is
A17. Aldehydes can be obtained as a result
1) hydration of alkenes
2) dehydration of alcohols
3) hydrohalogenation of alkynes
4) oxidation of primary alcohols
A18. In the transformation scheme
CH 3 CHO → X → C 2 H 4
substance X is
4) CH 3 CH 2 Cl
A19. During the dehydration reaction,
1) elimination of water
2) water connection
3) addition of hydrogen
4) elimination of hydrogen
A20. On reaction speed
CaCO 3 + 2HCl (p-p) = CaCl 2 + H 2 O + CO 2
does not affect change
1) pressure
2) temperature
3) concentration of hydrochloric acid
4) surface area of contact of substances
A21. On the shift of chemical equilibrium in the system 2HBr (g) ⇄ H 2 (g) + Br 2 (g) –Q
does not affect change
1) pressure
2) temperature
3) hydrogen concentration
4) concentration of hydrogen bromide
A22. A weak electrolyte is a substance whose formula is
A23. A precipitate forms during the interaction of solutions
1) potassium hydroxide and sulfurous acid
2) sodium sulfite and nitric acid
3) sodium bromide and iron (II) nitrate
4) chromium (III) chloride and lithium hydroxide
A24. For the human body, each of the two ions is most toxic
3) Pb 2+ and Hg 2+
4) Ca 2+ and Hg 2+
A25. Are the following statements about natural gas true?
A. The main components of natural gas are ethane and its homologues.
B. Natural gas serves as a raw material for the production of acetylene.
1) only A is correct
2) only B is correct
3) both judgments are correct
4) both judgments are incorrect
A26. The mass of water that needs to be added to 200 g of potassium nitrate solution with a mass fraction of 30% so that the mass fraction of salt in the solution becomes 10%
A27. As a result of a reaction, the thermochemical equation of which
2SO 2 (g) + O 2 (g) = 2SO 3 (g) + 198 kJ,
297 kJ of heat was released. The volume of sulfur (IV) oxide consumed is equal to
28. The volume of carbon dioxide (no.s.) resulting from the interaction of 5.3 g of sodium carbonate with an excess of hydrochloric acid solution is equal to
Cadmium. The content of cadmium in the body of an adult is 0.05 g. The specific physiological significance of cadmium has not been established, but its toxic effect on the human body is known: the metabolism of phosphorus, calcium, iron, copper is disrupted; hemoglobin synthesis is inhibited; Copper reserves in the liver and other organs sharply decrease; the activity of a number of enzymes is inhibited. Copper and zinc delay the toxic effect of cadmium (antagonism is observed between these elements in many cases).
Mercury. The human body contains approximately 0.013 g of mercury. Intake from food ranges from 2 to 30 mcg per day, accumulates mainly in the kidneys and brain. Disturbs the enzymatic, hormonal and immunological activity of proteins. It is a poison with pronounced toxic properties, both in metallic form and in the form of inorganic and organic compounds: almost all of them belong to hazard class I poisons.
Lead. The content in the body is 0.000001% (approximately 2 mg). Currently, the concentration of lead in plants, animal and human bones is constantly increasing due to widespread environmental pollution. The element is mainly (up to 90%) deposited in the bones and excreted mainly in the urine. It itself and its compounds are very toxic: they act mainly on the nervous, vascular system and directly on the blood; disrupt protein, carbohydrate, and phosphorus metabolism; cause hypovitaminosis C and B 1.
Currently, in international food trade, the following eight elements are subject to priority control: cadmium, mercury, lead, arsenic, copper, strontium, zinc, iron. The list of these elements is currently being expanded.
The effects of trace elements on humans and plants are described below.
Table 16
Impact of microelements on living organisms (humans)
| Element | Biological role | Toxic effects (large doses) |
| Fluorine | Has high biological activity. Concentrated in hair, bones, teeth (bone formation processes) | Inhibits the protective functions of the body: affects teeth (“fluoresis”), bones; causes bronchospasms. Acts on the mucous membrane of the eyes, liver, kidneys, myocardium |
| Silicon | Essential for epithelial and connective tissues. Its presence in the walls of blood vessels prevents the deposition of cholesterol. Promotes collagen biosynthesis | Large doses disrupt phosphorus-calcium metabolism and provoke the formation of stones in the urinary tract |
| Chromium | Performs intrasecretory functions. Part of trypsin, activates insulin, improves glucose absorption | The most toxic substances are compounds with a valency of 6. Irritates the mucous membranes of the respiratory tract. Affects the skin (ulcers) |
| Manganese | Activates many enzymatic processes: synthesis of hemoglobin, cholesterol and fatty acids. Improves glucose absorption. Mn deficiency leads to anemia | In case of poisoning, the exchange of biogenic amines and hormone formation are disrupted. Bone formations are disrupted (similar to rickets). The most toxic compounds are those with valency 2 |
| Iron | Part of hemoglobin: transfer of O 2 | Diseases of the internal respiratory tract, gastritis, gum inflammation - when working with iron vapor (in metallurgy) |
| Cobalt | Stimulates hematopoietic processes, promotes the absorption of Fe, Ca and P. Stimulates labor | In large doses it causes acute and chronic diseases. There is a change in the respiratory tract, blood, and a decrease in its coagulability. Anemia sometimes develops |
| Copper | Regulates the redox processes of cellular respiration and photosynthesis. Improves iron absorption. Affects water-salt metabolism | The entry of copper and its compounds into the stomach causes vomiting, liver damage, necrotic nephrosis |
| Zinc | Affects the function of the reproductive apparatus. It is part of insulin and has a positive effect on its secretion. Metal component of about 100 enzyme systems | Soluble zinc compounds are poisonous: they reduce Ca in the blood and bones; cause pain and swelling in the joints, diseases of the upper respiratory tract, dermatitis, anemia |
| Arsenic | Positively affects hematopoietic processes, participates in hemoglobin synthesis, redox processes, nucleic acid metabolism | Inhibits enzyme activity. Neuro-gastric, respiratory disorders. Damage to the blood, liver, kidneys |
| Selenium Se | Antioxidant: regulates lipid peroxidation. Essential for vision (in the retina). Needed for normal pregnancy | Apathy, lethargy, baldness, nail damage, caries. Damage to the skin, nervous system |
| Bromine | Contained in blood, cerebrospinal fluid, pituitary gland | Irritates mucous membranes, disrupts carbohydrate metabolism, and reduces kidney function. Long-term accumulation (“bromism”) leads to skin rashes and depression of the nervous system |
| Molybdenum | Part of enzymes that participate in nitrogen metabolism, affects copper metabolism | Long-term exposure causes gastritis and chronic cholecystitis. The contractile function of the heart is impaired, gynecological diseases are provoked |
| Silver Ag | Inert, functionally unimportant | With many years of work, strong pigmentation (“argyria”) of the skin appears. Enlarged liver, mental disorder |
| Cadmium | Contained in the liver and kidneys. No specific physiological effects detected | The exchange of P, Ca, Fe, Cu is disrupted. Hemoglobin synthesis is inhibited. Inhibits many enzymes |
| Tin Sn | Biological function not established | "Stannosis" - deposition of metals in the lungs; pneumoconiosis |
| Antimony | Biological function not established" | Pneumosclerosis, sexual dysfunction (m), gynecological diseases (w) |
| Iodine | Affects metabolism related to thyroid function | ¾ |
| Mercury | ¾ | Gastrointestinal tract disorder, decline in cardiac activity. Impaired function of the kidneys and endocrine glands |
| Lead | ¾ | Affects the nervous, vascular system, blood, disrupts protein, carbohydrate, and phosphorus metabolism. Causes hypovitaminosis C and B 1 |
Elements found in sufficient quantities in the body;
Table 17
The role of microelements in plant life
| Element | Biological role | Toxic effects | Sensitive crops |
| F | Citrate conversion | Necrosis of the edges and ends of leaves | Fruit trees, grapes |
| Al | Controls colloidal properties in cells | General growth retardation. Dying of the tips of the leaves, the root system is disfigured | Cereals |
| Si | Increased content in horsetails, sedges (“fragile plants”) - included in the plant skeleton | ¾ | ¾ |
| Cr | ¾ | Chlorosis of young leaves. Impedes root growth | All types of plants |
| Photoproduction of oxygen in chloroplasts | Chlorosis and necrotic leaf lesions | Cereals, legumes, cabbage, potatoes | |
| Fe | Photosynthesis, nitrogen fixation, redox reactions | Slow growth. Brown leaves | Rice, tobacco |
| Stimulation of ORR during the synthesis of chlorophyll and proteins. Symbiotic nitrogen fixation | Chlorosis of young leaves, ugly root tips | All types of plants | |
| Oxidation, photosynthesis, protein and carbohydrate metabolism | Root deformation, inhibition of shoot formation | Cereals, legumes, citrus fruits | |
| Metabolism of proteins and carbohydrates | Chlorosis and necrosis of leaves, growth retardation, root deformation | Cereals, spinach | |
| Metabolism of carbohydrates in algae | Red-brown dots on leaves, yellowing of roots, oppression of shoots | All types of plants | |
| Se | ¾ | Chlorosis or black spots - until completely blackened. Pinkish spots on roots | All types of plants |
| Nitrogen fixation. Catalyzes ORR | Yellow or brown leaves, suppressed root growth. Tillering inhibition | Cereals | |
| ¾ | Brown edges of leaves, their curling. Underdeveloped roots | Legumes, rice, oats | |
| ¾ | High toxicity to humans. For plants it is not completely clear | ¾ | |
| ¾ | Leaf chlorosis, brown spots. Inhibition of sprouts | Sugar beets, maize, roses | |
| ¾ | Dark green leaves, curling of old leaves, stunted foliage, brown short roots | All types of plants |
The most important biogenic microelements have been identified;
The most toxic microelements.
From these tables it is clear that the most important and necessary microelements
(Mn, Cu, Mo, Zn, Fe) at an increased dose cause pathological changes in both humans and plants. And at the same time, obviously toxic arsenic is necessary in small doses.
S-elements, their use in medicine and pharmacy .
Lithium -
1) Drugs relieve anxiety in mental patients.
2) Lithium benzoate in the composition of urodane - for gout, kidney and urinary stones, polyarthritis.
3) Li salts for electrophoresis in arthritis.
Sodium ( extracellular ion) -
1) NaCl (0.9% - physiological solution) for poisoning, vomiting, shock, blood loss, cholera (supports the acid-correct function and P osm of extracellular and intracellular fluids).
2) NaCl (5-10% - hypertonic solution) - for internal bleeding, for the treatment of purulent wounds.
3) NaHCO 3 - for high acidity, and externally - for washing mucous membranes, inhalations (thin the sputum): based on the anion.
4) Na 2 SO 4, Na 2 HAsO 4, Na 2 B 4 O 7, NaNO 2, Na 2 S 2 O 3 and others - based on the anion.
Potassium(intracellular ion) -
1) KCl, potassium orotate - for heart diseases, to maintain the normal rhythm of muscle work.
2) KSN 3 COO is a diuretic for edema associated with poor circulation and as a source of K + ions.
3) KBr, KJ, KClO 4, KMnO 4 and others - based on the anion.
Magnesium(intracellular ion) -
1) Soluble drugs - have a hypnotic, narcotic, anticonvulsant effect, reduce blood pressure:
MgSO 4 *7H 2 O (magnesia) - for convulsions, hypertension, diseases of the biliary tract, as a laxative; MgS 2 O 3 *6 H 2 O - for hypertension, atherosclerosis, coronary insufficiency, diseases of the biliary tract.
2) Insoluble drugs - internally or externally, have mainly an adsorbent and antacid effect: Mg(OH) 2 * 4MgCO 3 * H 2 O - white magnesia; MgO - burnt magnesia; MgO 2 * MgO (peroxide) - antimicrobial and astringent; Mg 2 Si 3 O 8 * nH 2 O (trisilicate) - for gastritis, ulcers (adsorbent and enveloping effect).
Calcium(extracellular ion) -
1) CaCl 2 * 6H 2 O - reduces vascular permeability, has anti-allergic and anti-inflammatory effects (prescribed for allergies, radiation sickness, rheumatism, bleeding and poisoning with a number of substances).
2) CaCO 3 - orally for diseases of the digestive tract (antacid and adsorbent).
3) CaSO 4 * 0.5H 2 O (gypsum) - for applying bandages for fractures and for taking impressions of the mouth in dentistry.
4) CaO - for disinfection.
5) Ca(OH) 2 - in dentistry (included in pastes)
Barium(poisonous!) -
1) BaSO 4 - in x-ray diagnostics of diseases of the digestive tract.
2) Ba(OH) 2 - in dentistry (as a catalyst in the manufacture of pastes and cements).
3) BaS (15% BaS and 85% talc) - the drug onycholysin is used to remove nail plates.