the first is a water molecule, the second is a carbon dioxide molecule, the third is a methane molecule, the fourth is a sulfur dioxide molecule.
Hello, please help me solve test 2 in chemistry8th grade
on the topic “Simple substances. Amount of substance."
Option 1.
A1. The sign of the element forming a simple substance – a non-metal:
1) Na 2) C 3) K 4) Al
A2. Simple substance – metal:
1) oxygen 2) copper 3) phosphorus 4) sulfur
A3. The physical state of the simple substance mercury at normal
conditions:
1) solid 2) liquid 3) gaseous
A4. The chemical bond is covalent nonpolar
in substance:
1) iron 2) chlorine 3) water 4) copper
A5. Allotropic modification of oxygen:
1) graphite 2) white phosphorus 3) ozone 4) coal
A6. The notation 3O2 means:
1) 2 oxygen molecules
2) 3 oxygen molecules
3) 5 oxygen atoms
4) 6 oxygen atoms
A7. The mass of 3 moles of hydrogen sulfide H2S is equal to:
1) 33 2) 34 3) 99 4) 102
A8. The volume occupied by 2 moles of a gaseous substance with
formula SO2 (n.s):
1)22.4 l. 2) 33.6 l. 3) 44.8 l. 4) 67.2 l.
A9. A group of substances with an ionic type of chemical bond:
1) Cl2, H2, O2 2) KCl, NaBr, CaI2
3) H2O, CO2, NaCl 4) K2O, MgO, NaI
A10. Molar volume is. . .
1) volume of any gas at no. 2) volume of 2 g of any gas at zero
3) volume of 1 mole of any gas at no. 4) volume of 12 * 1023 molecules at no.
A11. 3 chlorine molecules:
1)3Cl2 2)3Cl 3)Cl2 4)6Cl
Q1. Identify a hard, soft substance that leaves a mark on paper, has a slight metallic luster, and is electrically conductive:
1) diamond 2) coal 3) graphite 4) white phosphorus
AT 2. The number of molecules in 2 mmol of water is:
1) 12*1023. 2) 12*1020. 3) 18*1020 4) 12*1018
AT 3. Substances arranged in increasing order of non-metallic
properties:
1) K, Na, Rb, Li 2) Li, Na K, Rb 3) Rb, K, Na, Li 4) Na, Rb, K, Li
C1. Calculate the volume of 140 kg. nitrogen N2 at no.
A.Na B.C C.K D.Al
2) Simple substance - metal:
A. oxygen B. Copper C. Phosphorus D. Sulfur
3) The physical state of the simple substance mercury under normal conditions:
A. Solid B. Liquid C. Gaseous
4) The chemical bond is covalent nonpolar in a substance:
A. Iron B. Liquid C. Gaseous
5) Allotropic modification of oxygen:
A. Graphite B. Ozone
B. White phosphorus D. Diamond
6) An atom of an element forming a simple substance - metal, corresponds to an electronic diagram:
A. +18))) B. +3)) C. +6)) D. +15)))
288 21 24 285
7) The entry ZO2 means:
A. 2 oxygen molecules
B. 3 oxygen molecules
B. 5 oxygen atoms
D. 3 oxygen atoms
8) The mass of 3 moles of hydrogen sulfide H2S is equal to: (with solution)
A. 33 g. B. 34 g. C. 99 g. D. 102 g.
9) The volume occupied by 2 moles of a gaseous substance with the formula SO2 (n.s.): (with solution)
A. 22.4 l. B. 33.6 l. H. 44.8 l. G. 67.2 l.
10) the amount of carbon dioxide CO2, which contains 36*10(23) molecules, is equal to: (with solution)
11) Match:
Type of chemical bond:
1. Ionic B. Covalent polar C. Metallic
Chemical formula of the substance:
A.CI2 B.K C.NaCI D.Fe D.NH3
12) Calculate the volume of oxygen O2 with a mass of 160 g (no.) (with solution)
13) Complete the definition: “Allotropy is a phenomenon...”
14) Select the properties that characterize graphite.
A. Hard
B. Soft, leaves marks on paper.
B. Colorless, transparent.
D. Has a slight metallic luster
D. Electrically conductive.
level 3 electrons?
1) Mg and Al 2) O and S 3) N and S 4) B and Al
2. An atom of an element forming a simple substance - a nonmetal - corresponds to
electronic circuit?
1) +11)2)8)1 2) +8)2)6 3) +12)2)8)2 4) +4)2)2
3. Nitrogen exhibits the highest degree of oxidation when combined with the formula:
1) NO2 2)NO 3)NH3 4)N2O5
4. Which substance has a covalent nonpolar bond?
1) O2 2) H2O 3) CaCl2 4) Ba
5. The electronic formula 1s2 2s2 2p1 corresponds to the atom:
1) beryllium 2) silicon 3) carbon 4) boron
6. With an increase in the charge of atomic nuclei in the series F -Cl - Br -I, nonmetallic
properties?
1) intensify 2) weaken 3) do not change 4) change periodically
7. indicate the formula of a compound with a covalent polar chemical bond:
1) H2 2) NH3 3) Ca3N2 4) C
8. The degree of oxidation of phosphorus in the compounds P2O5, PH3, Ca3P2, respectively
equal?
1) +3, -3, +5 2) -3, +3, +5 3) +5, +5, -3 4) +5, -3, -3
9. Are the following statements true?
A. In the period, the metallic properties of atoms of elements with increasing order
the numbers are getting stronger.
B. In the period, the metallic properties of atoms of elements with increasing order
numbers are weakening.
1) only A is true 2) Both judgments are true 3) only B is true 4) both judgments are not
are true
10. A chemical element in the atom of which the electrons are distributed among the layers as follows:
2,8,8,2, in the periodic table there is:
A) in the 4th period, 2nd group, secondary subgroup
B) in the 4th period, 2nd group of the main subgroup
B) in the 3rd period, 5th group of the main subgroup
D) in the 3rd period, 5th group, secondary subgroup
organic chemistry molecule isology
It is now generally accepted that one straight line connecting two atoms denotes one two-electron bond (single bond), the formation of which requires one valency from each of the bonded atoms, two lines - one four-electron bond (double bond), three lines - one six-electron bond (triple bond).
A representation of a compound with a known order of bonds between all atoms using bonds of this type is called a structural formula:
To save time and space, abbreviated formulas are often used, in which some of the connections are implied but not written:
Sometimes, especially in the carbocyclic and heterocyclic series, the formulas are simplified even further: not only are some bonds not written, but also some of the carbon and hydrogen atoms are not depicted, but are only implied (at the intersections of the lines); simplified formulas:
Tetrahedral model of the carbon atom
The basic ideas about the chemical structure laid down by A. M. Butlerov were supplemented by Van't Hoff and Le Bel (1874), who developed the idea of the spatial arrangement of atoms in the molecule of an organic substance and raised the question of the spatial configuration and conformation of molecules. Van't Hoff's work “Chemistry in Space” (1874) marked the beginning of a fruitful direction in organic chemistry - stereochemistry, i.e. the study of spatial structure.
Rice. 1 - Van't Hoff models: methane (a), ethane (b), ethylene (c) and acetylene (d)
Van't Hoff proposed a tetrahedral model of the carbon atom. According to this theory, the four valencies of the carbon atom in methane are directed towards the four corners of the tetrahedron, in the center of which there is a carbon atom, and at the vertices are hydrogen atoms (a). Ethane, according to Van't Hoff, can be imagined as two tetrahedrons connected at the vertices and freely rotating about a common axis (6). The model of the ethylene molecule represents two tetrahedra connected by edges (c), and molecules with a triple bond are represented by a model in which the tetrahedra are in contact with planes (d).
Models of this type have also proven to be very successful for complex molecules. They are successfully used today to explain a number of stereochemical questions. The theory proposed by Van't Hoff, although suitable in almost all cases, did not, however, provide a reasonable explanation of the type and essence of binding forces in molecules.
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GBPOU NSO "Kolyvan Agrarian College"
Instructional technological map No. 1
according to OUD. eleven Chemistry
professions 35.01.23 Mistress of the estate, 01/19/04 Baker
Section 1: Organic Chemistry
Topic 1.1: Basic concepts of organic chemistry and the theory of the structure of organic compounds.
Job title : Making models of molecules - representatives of various classes of organic compounds.
Goal of the work:
generalize and systematize students’ knowledge about the theory of the structure of organic compounds;
consolidate the ability to compose structural formulas of hydrocarbons;
The student must achieve the following results:
personal:
− a sense of pride and respect for the history and achievements of domestic chemical science; chemically competent behavior in professional activities and at home when handling chemicals, materials and processes;
− readiness to continue education and advanced training in the chosen professional activity and objective awareness of the role of chemical competencies in this;
− the ability to use the achievements of modern chemical science and chemical technologies to improve one’s own intellectual development in the chosen professional activity;
meta-subject:
− the use of various types of cognitive activity and basic intellectual operations (statement of the problem, formulation of hypotheses, analysis and synthesis, comparison, generalization, systematization, identification of cause-and-effect relationships, search for analogues, formulation of conclusions) to solve the problem, the use of basic methods of cognition (observation, scientific experiment) to study various aspects of chemical objects and processes that need to be encountered in the professional field;
− the use of various sources to obtain chemical information, the ability to assess its reliability in order to achieve good results in the professional field;
subject :
− the formation of ideas about the place of chemistry in the modern scientific picture of the world;
Understanding the role of chemistry in shaping a person’s horizons and functional literacy for solving practical problems;
− mastery of fundamental chemical concepts, theories, laws and patterns;
Confident use of chemical terminology and symbols;
− mastery of the basic methods of scientific knowledge used in chemistry: observation, description, measurement, experiment;
Ability to process, explain the results of experiments and draw conclusions;
− willingness and ability to apply cognitive methods in solving practical problems;
− developed ability to give quantitative estimates and make calculations using chemical formulas and equations;
− knowledge of safety rules when using chemicals;
− formation of one’s own position in relation to chemical information obtained from various sources.
Form of study : individual
Standard time: 2 hours
Workplace equipment : A set of ball-and-stick models of molecules, table “Saturated hydrocarbons”, periodic table, instructional technology cards, notebooks
Literature:
Means of education: verbal (verbal), visual
Safety precautions: familiarized with safety rules at the workplace and in the office.
Guidelines
Hydrocarbons are organic substances consisting of carbon and hydrogen atoms. The carbon atom in all organic compounds is tetravalent. Carbon atoms can form straight, branched, and closed chains. The properties of substances depend not only on the qualitative and quantitative composition, but also on the order in which the atoms are connected to each other. Substances that have the same molecular formula but different structures are called isomers. Prefixes indicate quantitydi - two,three - three,tetra - four;cyclo - means closed.
Suffixes in the names of hydrocarbons indicate the presence of a multiple bond:
en
single bond between carbon atoms(C - C);
en
double bond between carbon atoms(C = C);
in
triple bond between carbon atoms(WITH
=
WITH);
diene
two double bonds between carbon atoms(C = C - C = C);
Radicals:methyl -CH 3 ; ethyl -C 2 N 5 ; chlorine -Cl; bromine -Br.
Example. Make a model of a propane molecule.
Propane moleculeC 3 H 8 contains three carbon atoms and eight hydrogen atoms. The carbon atoms are connected to each other. Suffix– en indicates the presence of a single bond between carbon atoms. Carbon atoms are located at an angle of 109 28 minutes.
The molecule has the shape of a pyramid. Draw carbon atoms as black circles, hydrogen atoms as white circles, and chlorine atoms as green circles.
When drawing models, observe the ratio of atomic sizes.
Find the molar mass using the periodic table
M(S 3 N 8 ) = 12 · 3 + 1 · 8 = 44 g/mol.
To name a hydrocarbon you need to:
Choose the longest chain.
Number starting from the edge to which the radical or multiple bond is closest.
Indicate the radical if several radicals are indicated each. (Number before the name).
Name the radical, starting with the smallest radical.
Name the longest chain.
Indicate the position of the multiple bond. (Number after name).
Example
When composing formulas by name, you need to:
Determine the number of carbon atoms in the chain.
Determine the position of the multiple bond. (Number after name).
Determine the position of radicals. (Number before the name).
Write down the formulas of radicals.
Lastly, determine the number and arrangement of hydrogen atoms.
Work order
Task No. 1 . Make models of molecules:
1) a number of alkanes: methane, ethane, butane, pentane, hexane, heptane, octane, nonane and decane;
2) Cycloalkanes: cyclopropane,cyclopetane
3) 2-methylpropane,
4) 1,2-dichloroethane.
Draw molecular models in your notebook. Write the structural formulas of these substances. Find their molecular weights.
Task No. 2. Name the substances:
Task No. 3. Compose structural formulas of substances:
a) butene-2, write its isomer;
b) 3,3 - dimethylpentine-1.
Control questions
Give the general formula for saturated hydrocarbons.
Which substances are called homologues and which are isomers?
Teacher: Rachkovskaya A.I.
Organic chemistry.
2.1.Topic: " Theory of the structure of organic compounds"
2.1.1. Basic principles of the theory of the structure of organic compounds and classification of organic compounds.
1. Natural and synthetic organic substances. A little from the history of organic chemistry. General properties of organic substances (composition, type of chemical bond, crystal structure, solubility, relationship to heating in the presence of oxygen and without it).
2. The theory of the structure of organic compounds by A.M. Butlerov. Development of the theory and its significance.
3. Classification of organic substances.
Organic substances received their name because the first of the studied substances of this group were part of living organisms. Most of the currently known organic substances are not found in living organisms; they are obtained (synthesized) in the laboratory. Therefore, a distinction is made between natural (natural) organic substances (although most of them can now be obtained in the laboratory), and organic substances that do not exist in nature - synthetic organic substances. Those. The name “organic substances” is historical and does not have much meaning. All organic compounds are carbon compounds. Organic substances include carbon compounds, except for the simple substances formed by carbon, its oxides, carbonic acid and its salts studied in the course of inorganic chemistry. In other words: organic chemistry is the chemistry of carbon compounds.
Brief history of the development of organizational chemistry:
Berzelius, 1827, first textbook of organic chemistry. Vitalists. The doctrine of "life force".
The first organic syntheses. Wöhler, 1824, synthesis of oxalic acid and urea. Kolbe, 1845, acetic acid. Berthelot, 1845, fat. Butlerov, 1861, sugary substance.
But as a science, organic chemistry began with the creation of a theory of the structure of organic compounds. A significant contribution to it was made by the German scientist F.A. Kekule and the Scotsman A.S. Cooper. But the decisive contribution undoubtedly belongs to the Russian chemist A.M. Butlerov.
Among all elements, carbon stands out for its ability to form stable compounds in which its atoms are linked to each other in long chains of various configurations (linear, branched, closed). The reason for this ability: approximately the same bond energy of C-C and C-O (for other elements the energy of the second is much higher). In addition, a carbon atom can be in one of three types of hybridization, forming single, double or triple bonds, respectively, not only with each other, but also with oxygen or nitrogen atoms. True, much more often (almost always) carbon atoms are connected to hydrogen atoms. If an organic compound contains only carbon and hydrogen, the compounds are called hydrocarbons. All other compounds can be considered as derivatives of hydrocarbons in which some hydrogen atoms are replaced by other atoms or groups of atoms. Therefore, a more precise definition:
There are a lot of organic compounds - more than 10 million (about 500 thousand inorganic). The composition, structure and properties of all organic substances have much in common.
Organic substances have a limited qualitative composition. Necessarily C and H, often O or N, less often halogens, phosphorus, sulfur. Other elements are included very rarely. But the number of atoms in a molecule can reach millions, and the molecular weight can be very large.
Structure of organic compounds. Because composition - non-metals. => Chemical bond: covalent. Non-polar and polar. Ionic very rarely. => Crystal lattice most often molecular.
General physical properties: low boiling and melting point. Organic substances include gases, liquids and fusible solids. Often volatile and may have an odor. Usually colorless. Most organic substances are insoluble in water.
General chemical properties:
1) when heated without air access, all organic substances become “charred”, i.e. in this case, coal (more precisely, soot) and some other inorganic substances are formed. Covalent bonds are broken, first polar, then non-polar.
2) When heated in the presence of oxygen, all organic substances are easily oxidized, and the final products of oxidation are carbon dioxide and water.
Features of the course of organic reactions. Organic reactions involve molecules; during the reaction, some covalent bonds must be broken and others formed. Therefore, chemical reactions involving organic compounds usually proceed very slowly; they require the use of elevated temperature, pressure, and catalysts. Inorganic reactions usually involve ions; the reactions proceed very quickly, sometimes instantly, at normal temperature. Organic reactions rarely result in high yields (usually less than 50%). They are often reversible; in addition, not one, but several reactions may occur, competing with each other, which means the reaction products will be a mixture of different compounds. Therefore, the form of recording organic reactions is also somewhat different. Those. they do not use chemical equations, but chemical reaction schemes in which there are no coefficients, but the reaction conditions are indicated in detail. It is also customary to write down the names of the org under the equation. substances and type of reaction.
But in general, organic substances and reactions obey the general laws of chemistry, and organic substances turn into inorganic ones or can be formed from inorganic ones. Which once again emphasizes the unity of the world around us.
The basic principles of the theory of chemical structure, set out by the young A.M. Butlerov at the international congress of natural scientists in 1861.
1). Atoms in molecules are connected to each other in a certain order, in accordance with their valency. The sequence of combination of atoms is called chemical structure .
Valency is the ability of atoms to form a certain number of bonds (covalent). Valency depends on the number of unpaired electrons in an atom of an element because covalent bonds are formed by sharing electron pairs when electrons are paired. Carbon in all organic substances is tetravalent. Hydrogen - 1, Oxygen - P, nitrogen - Ш, sulfur - P, chlorine - 1.
Methods for depicting organic molecules.
A molecular formula is a conventional representation of the composition of a substance. H 2 CO 3 - carbonic acid, C 12 H 22 O 11 - sucrose. Such formulas are convenient for calculations. But they do not provide information about the structure and properties of the substance. Therefore, even molecular formulas in organics are written in a special way: CH 3 OH. But much more often they use structural formulas. The structural formula reflects the order in which atoms are connected in a molecule (i.e., chemical structure). And at the basis of any organic molecule is carbon skeleton is a chain of carbon atoms interconnected by covalent bonds.
Electronic formulas of molecules - bonds between atoms are shown in pairs of electrons.
The complete structural formula shows all connections with dashes. A chemical bond formed by one pair of electrons is called a single bond and is represented by a single line in the structural formula. A double bond (=) is formed by two pairs of electrons. Triple (≡) is formed by three pairs of electrons. And the total number of these bonds must correspond to the valency of the element.
In a condensed structural formula, the dashes of single bonds are omitted, and the atoms associated with one or another carbon atom are written immediately after it (sometimes in parentheses).
Skeletal formulas are even more abbreviated. But they are used less often. For example:
Structural formulas reflect only the order of joining of atoms. But molecules of organic compounds rarely have a flat structure. The three-dimensional image of a molecule is important for understanding many chemical reactions. The image of a molecule is described using concepts such as bond length and bond angle. In addition, free rotation around single bonds is possible. Molecular models provide a visual representation.
7.1. The figure shows an experiment illustrating that bodies expand when heated. With a pen, circle in the picture the object that was heated in this experiment - a ball or a ring. Justify your answer.
7.2. Choose the correct statement.
According to modern ideas, when a flask with water cools, the water level in the tube drops because... . 
7.3. Substances are made up of tiny particles. What phenomena and experiments confirm this?
7.4. The table shows exact data on the change in the volume of water V as a function of time t during heating.
Answer the questions.
a) Is it possible to say that during the entire observation time the water in the flask was heated evenly? Explain your answer.
b) How did the volume of water change when heated?
8.1. Choose the correct statement.
If you heat a nail, it lengthens and becomes thicker. This happens because when heated... . 
8.2. Write the words molecule, drop, atom in such an order that each subsequent element is part of the previous one.
8.3. The figure shows models of molecules of water, oxygen and carbon dioxide. All molecules contain an oxygen atom (black). Fill in the blanks in the text.
8.4. Measure the length of your arm from your elbow to your little finger and compare the measurement to the size of a water molecule.
9.1. Fill in the blanks in the text. “In ____, the English botanist Robert Brown, looking through a microscope...”
9.2. The figure schematically shows liquid molecules surrounding a grain of paint placed in this liquid. The arrows indicate the direction of movement of liquid molecules at a certain point in time.
9.3. List those phenomena that are examples of Brownian motion.
9.4. The figure shows a broken line along which a speck of dust moved in the air for several seconds.
a) Explain why the speck of dust changed the direction of its movement many times during the observation of it.
Due to collisions with air molecules and other dust particles.
b) In the figure, indicate the points at which the dust particle was affected by the molecules surrounding it.
10.1. Pure water is poured into a glass cylinder from above, and a solution of copper sulfate is poured into the bottom through a narrow tube. The cylinder is at rest when constant temperature. Show in the figure what the contents of the cylinder will look like at various intervals.
10.2. Two identical rubber balls are connected by a transparent hose (see figure), and the left ball in both cases is filled with hydrogen (color the hydrogen blue), the right one is empty in figure a, and is filled with air in figure b (color the air green). The hose is clamped between the balls.
10.3. Cross out one of the highlighted words to complete the correct explanation of the experiment described.
10.4. Home experiment.
Place a piece of sugar at the bottom of a glass of cold water, but do not stir. Write down how long it took you to detect the presence of sugar molecules on the surface of the water in the glass and what “device” you used.
11.1. Fill in the gaps in the text using the words: stronger; weaker; attraction; repulsion.
11.2. Connect the phenomena and their corresponding explanations with lines.
11.3. Cross out one of the highlighted words to complete the correct explanation of the experiment described.
11.4. Complete the sentence to get the correct explanation of the phenomenon.
11.5. Fill in the blanks in the text. “In everyday life, we often encounter the phenomena of wetting and non-wetting.”
12.1. What state of matter is characterized by the listed characteristics?
