Practical work on the topic "Making models of molecules - representatives of various classes of organic compounds". The structure of matter Models of molecules of various substances
Today we will conduct a lesson not only in modeling, but also in chemistry, and we will mold models of molecules from plasticine. Plasticine balls can be imagined as atoms, and ordinary matches or toothpicks will help show structural bonds. This method can be used by teachers when explaining new material in chemistry, parents - when checking and studying homework, and children themselves who are interested in the subject. An easier and more affordable way to create visual material for mental visualization of micro-objects is perhaps not found.
Here are representatives from the world of organic and inorganic chemistry as an example. By analogy with them, other structures can be executed, the main thing is to understand all this diversity.
Materials for work:
- plasticine of two or more colors;
- structural formulas of molecules from the textbook (if necessary);
- matches or toothpicks.
1. Prepare plasticine for sculpting spherical atoms, from which molecules will be formed, as well as matches - to represent the bonds between them. Naturally, it is better to show atoms of different kinds in a different color in order to make it clearer to imagine a specific object of the microworld.
2. To make balls, pinch off the required number of servings of plasticine, knead in your hands and roll the figures in your palms. To sculpt organic hydrocarbon molecules, you can use larger red balls - this will be carbon, and blue smaller ones - hydrogen.
3. To mold a methane molecule, insert four matches into the red ball so that they are directed to the vertices of the tetrahedron.
4. Put blue balls on the free ends of the matches. The natural gas molecule is ready.
5. Prepare two identical molecules to explain to your child how to get the next hydrocarbon molecule - ethane.
6. Connect the two models by removing one match and two blue balls. Ethan is ready.
7. Next, continue your fun activity and explain how the multiple connection is formed. Remove the two blue balls, and make the bond between the carbons double. In a similar way, you can mold all the hydrocarbon molecules necessary for occupation.
8. The same method is suitable for modeling the molecules of the inorganic world. The same plasticine balls will help to carry out the plan.
9. Take the central carbon atom - the red ball. Insert two matches into it, setting the linear shape of the molecule, attach two blue balls to the free ends of the matches, which in this case represent oxygen atoms. Thus, we have a linear carbon dioxide molecule.
10. Water is a polar liquid and its molecules are angular formations. They are made up of one oxygen atom and two hydrogen atoms. The angular structure is determined by the lone pair of electrons on the central atom. It can also be depicted as two green dots.
These are fun creative lessons that you should definitely practice with children. Students of any age will be interested in chemistry and will better understand the subject if, in the process of studying, they are provided with a visual aid made with their own hands.
the first is a water molecule, the second is a carbon dioxide molecule, the third is a methane molecule, and the fourth is a sulfur dioxide molecule.
Hello, please help me solve test 2 in chemistry8th grade
on the topic “Simple substances. The amount of substance ”.
Option 1.
A1. The sign of the element forming a simple substance is 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 state of aggregation of a simple substance of mercury under ordinary
conditions:
1) solid 2) liquid 3) gaseous
A4. The chemical bond is covalent non-polar
in substance:
1) iron 2) chlorine 3) water 4) copper
A5. Allotropic oxygen modification:
1) graphite 2) white phosphorus 3) ozone 4) coal
A6. Recording 3O2 means:
1) 2 oxygen molecules
2) 3 oxygen molecules
3) 5 oxygen atoms
4) 6 oxygen atoms
A7. The mass of 3 mol of hydrogen sulfide H2S is:
1) 33 g. 2) 34 g. 3) 99 g. 4) 102 g.
A8. The volume that takes 2 mol of a gaseous substance with
formula SO2 (n.y):
1) 22.4 liters. 2) 33.6 liters. 3) 44.8 liters. 4) 67.2 liters.
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) the volume of any gas at n.a. 2) the volume of 2 g of any gas at standard
3) the volume of 1 mole of any gas at normal conditions 4) the volume of 12 * 1023 molecules at normal conditions
A11. 3 chlorine molecules:
1) 3Cl2 2) 3Cl 3) Cl2 4) 6Cl
B1 Identify a hard soft substance leaving a mark on paper, has a faint metallic luster, 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 in ascending 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 normal conditions
A.Na B.C B.K G.Al
2) Simple substance - metal:
A. oxygen B. Copper C. Phosphorus D. Sulfur
3) Physical state of a simple substance of mercury under normal conditions:
A. Solid B. Liquid C. Gaseous
4) The chemical bond is covalent non-polar 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 that forms a simple substance - metal, corresponds to an electronic circuit:
A. +18))) B. +3)) V. +6)) G. +15)))
288 21 24 285
7) Recording ZO2 means:
A. 2 oxygen molecules
B. 3 oxygen molecules
B. 5 oxygen atoms
D. 3 oxygen atoms
8) The mass of 3 mol of hydrogen sulfide H2S is: (with a solution)
A. 33 B. 34 C. 99 G. 102
9) The volume that takes 2 mol of a gaseous substance with the formula SO2 (n.a.): (with a solution)
A. 22.4 liters. B. 33.6 l. H. 44.8 liters. G. 67.2 l.
10) the amount of substance carbon dioxide CO2, which contains 36 * 10 (23) molecules, is equal to: (with a solution)
11) Correlate:
Chemical bond type:
1. Ionic B. Covalent polar C. Metallic
Chemical formula of the substance:
A.CI2 B.K B.NaCI G.Fe D.NH3
12) Calculate the volume of oxygen O2 weighing 160 g (n.a.) (with solution)
13) Complete the definition: "Allotropy is a phenomenon ..."
14) Select properties that characterize graphite.
A. Solid
B. Soft, Leaves marks on paper.
B. Colorless, transparent.
D. Has a weak 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. The atom of the element, which forms a simple substance - a non-metal, corresponds
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 oxidation state in combination with the formula:
1) NO2 2) NO 3) NH3 4) N2O5
4. Which of the substances has a covalent non-polar 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 the nuclei of atoms in the series F -Cl - Br -I, non-metallic
properties?
1) increase 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 oxidation state of phosphorus in 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 an increase in the ordinal
numbers are enhanced.
B. In the period, the metallic properties of atoms of elements with an increase in the ordinal
the numbers are waning.
1) only A is true 2) Both statements are true 3) only B is true 4) both statements are not
are true
10. A chemical element in whose atom electrons are distributed over layers as follows:
2,8,8,2, in the periodic system is:
A) in the 4th period, the 2nd group of the side subgroup
B) in the 4th period, the 2nd group of the main subgroup
B) in the 3rd period, the 5th group of the main subgroup
D) in the 3rd period, the 5th group of the side subgroup
organic chemistry molecule isology
It is now generally accepted that one straight line connecting two atoms denotes one two-electron bond (simple bond), the formation of which takes one valency from each of the bonded atoms, two lines - one four-electron bond (double bond), three lines - one six-electron bond (triple bond).
The image of a compound with a known order of bonds between all atoms using bonds of this type is called the structural formula:
To save time and space, abbreviated formulas are often used, in which some of the links are implied, but not written:
Sometimes, especially in carbocyclic and heterocyclic series, formulas are simplified even more: not only some bonds are not written, but some of the carbon and hydrogen atoms are not depicted, but only implied (at the intersection of lines); simplified formulas:
Tetrahedral model of the carbon atom
The basic concepts of the chemical structure laid down by A.M.Butlerov were supplemented by Van't Hoff and Le-Belle (1874), who developed the idea of \u200b\u200bthe spatial arrangement of atoms in an organic molecule and raised the question of the spatial configuration and conformation of molecules. Van't Hoff's work "Chemistry in Space" (1874) laid the foundation for the fruitful direction of organic chemistry — stereochemistry, that is, the study of spatial structure.
Figure: 1 - Van't Hoff models: methane (a), ethane (b), ethylene (c) and acetylene (d)
Van't Hoff proposed a tetrahedral model for the carbon atom. According to this theory, the four valences of the carbon atom in methane are directed to the four corners of the tetrahedron, in the center of which there is a carbon atom, and at the vertices there are hydrogen atoms (a). Ethane, according to Van't Hoff, can be imagined as two tetrahedra connected by vertices and freely rotating about a common axis (6). The model of an ethylene molecule is represented by two tetrahedra connected by edges (c), and molecules with a triple bond are depicted by a model in which the tetrahedra are in contact with planes (d).
Models of this type have proved to be very successful for complex molecules. They are successfully used today to explain a number of stereochemical issues. The theory proposed by Van't Hoff, although applicable in almost all cases, did not, however, provide a valid explanation of the type and nature of the binding forces in molecules.
An innovative way of developing the technology for creating new drugs
First, a computer model of the object is created, and computer modeling is also used to form molecules at the research site. The model can be either two-dimensional or three-dimensional ...
Infrared spectra of molecules
In contrast to the visible and ultraviolet ranges, which are mainly due to the transitions of electrons from one stationary state to another ...
Investigation of the structure of organic compounds using physical methods
All possible positions of molecules in three-dimensional space are reduced to translational, rotational and oscillatory motion. A molecule consisting of N atoms has only 3N degrees of freedom of motion ...
Modeling method in chemistry
Currently, you can find many different definitions of the concepts of "model" and "simulation". Let's consider some of them. “A model is understood as the display of facts, things and relations of a certain area of \u200b\u200bknowledge in the form of a simpler ...
Scientific foundations of rheology
In general, the stress-strain state of a body is three-dimensional and it is unrealistic to describe its properties using simple models. However, in those rare cases when uniaxial bodies are deformed ...
In addition to observation and experiment, modeling plays an important role in understanding the natural world and chemistry. One of the main goals of observation is to find patterns in the results of experiments ...
Dissolving solids
For the vast majority of processes, the kinetic function is invariant with respect to the concentration of the active reagent and temperature. In other words, each value of the dimensionless time x corresponds to a well-defined value ...
Calculation of the quantum-chemical parameters of PAS and determination of the structure-activity relationship using the example of sulfonamides
Refractometric method of analysis in chemistry
Synthesis and analysis of CTS in gasoline production
The chemical model of the catalytic cracking process is very complex. Let us consider the simplest of the reactions occurring throughout the cracking process: СnН2n + 2\u003e CmH2m + 2 + CpH2p ...
Synthesis of a chemical technological system (CTS)
Manufacturing processes are diverse in their characteristics and degree of complexity. If the process is complex and deciphering its mechanism requires a lot of effort and time, use an empirical approach. Mathematical models ...
Comparison of plug-flow and fully-mixed reactors in isothermal operation
Organic chemistry.
2.1. Topic: " Theory of the structure of organic compounds "
2.1.1. The main provisions of the theory of the structure of organic compounds and the classification of organic compounds.
1. Natural and synthetic organic substances. A bit from the history of organic chemistry. General properties of organic substances (composition, type of chemical bond, crystal structure, solubility, attitude to heating in the presence of oxygen and without it).
2. Theory of the structure of organic compounds AM Butlerov. The development of the theory and its significance.
3. Classification of organic substances.
Organic substances got 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, natural (natural) organic substances are distinguished (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 has no special meaning. All organic compounds are carbon compounds. Organic substances include carbon compounds, except for those studied in the course of inorganic chemistry of simple substances formed by carbon, its oxides, carbonic acid and its salts. In other words: organic chemistry is the chemistry of carbon compounds.
A brief history of the development of organic chemistry:
Berzelius, 1827, the 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, sugar 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 the 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 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, respectively, single, double or triple bonds, and not only with each other, but also with oxygen or nitrogen atoms. True, much more often (almost always) carbon atoms are combined with hydrogen atoms. If the organic compound contains only carbon and hydrogen, then the compounds are called hydrocarbons. All other compounds can be considered as derivatives of hydrocarbons, in which some of the hydrogen atoms are replaced by other atoms or groups of atoms. Therefore, a more precise definition is: Organic compounds are hydrocarbons and their derivatives.
There are a lot of organic compounds - more than 10 million (inorganic about 500 thousand). The composition, structure and properties of all organic substances have much in common.
Organic matter has a limited qualitative composition... Necessarily C and H, often O or N, less often halogens, phosphorus, sulfur. Other elements are very rare. But the number of atoms in a molecule can reach millions, and the molecular weight can be very large.
The structure of organic compounds. Because composition - non-metals. \u003d\u003e Chemical bond: covalent... Non-polar and polar. Ionic is very rare. \u003d\u003e Crystalline grid most often molecular.
General physical properties: low boiling point and melting point. Organic substances include gases, liquids, and low-melting solids. Often volatile, 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 are "charred"; in this case, coal (more precisely, soot) and some other inorganic substances are formed. There is a rupture of covalent bonds, first polar, then non-polar.
2) When heated in the presence of oxygen, all organic substances are easily oxidized, and the end products of oxidation are carbon dioxide and water.
Features of the course of organic reactions. Molecules are involved in organic reactions; during the reaction, some covalent bonds must break and others are formed. Therefore, chemical reactions with the participation of organic compounds are usually very slow, to carry them out, it is necessary to use an increased temperature, pressure and catalysts. Inorganic reactions usually involve ions, the reactions proceed very quickly, sometimes instantly, at normal temperature. Organic reactions rarely lead to high yields (typically less than 50%). They are often reversible, in addition, not one, but several reactions, competing with each other, can occur, which means that the reaction products will be a mixture of different compounds. Therefore, the form of recording organic reactions is also somewhat different. Those. they use not chemical equations, but schemes of chemical reactions, 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. substances and the type of reaction.
But in general, organic substances and reactions obey the general laws of chemistry, and organic substances are converted into inorganic ones or can be formed from inorganic ones. This once again emphasizes the unity of the world around us.
The basic principles of the theory of chemical structure, presented by the young A.M. Butlerov at the International Congress of Naturalists in 1861.
1). The atoms in molecules are connected to each other in a certain order, in accordance with their valence. The sequence of joining atoms is called chemical structure. .
Valence is the ability of atoms to form a certain number of bonds (covalent). The valence depends on the number of unpaired electrons in the element's atom, because covalent bonds are formed due to shared electron pairs when electrons are paired. Carbon in all organic substances is tetravalent. Hydrogen - 1, Oxygen - P, nitrogen - III, sulfur - P, chlorine - 1.
Methods for imaging organic molecules.
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 organic matter are written in a special way: CH 3 OH. But structural formulas are used much more often. The structural formula reflects the order in which atoms are joined in a molecule (i.e. chemical structure).And any organic molecule is based on carbon skeleton is a chain of covalently bonded carbon atoms.
Electronic formulas of molecules - bonds between atoms are shown by pairs of electrons.
The complete structural formula is shown with dashes. A chemical bond formed by one pair of electrons is called a single bond and is represented by a single dash in the structural formula. The double bond (\u003d) is formed by two pairs of electrons. The triple (≡) is formed by three pairs of electrons. And the total number of these bonds must correspond to the valence of the element.
In the condensed structural formula, 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 in which atoms are joined. But molecules of organic compounds rarely have a flat structure. The 3D 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.
