Ask a few junior high school chemistry questions and ask a few junior high school chemistry question

1.Acetic acid is an organic substance.

2.Generally speaking, metals are easy to lose electrons, and non-metals are easy to get electrons, when metals and nonmetals form compounds, metals will lose outer electrons to non-metals, so that metals form cations, and nonmetals form anions, NaCl is Na loses an outer electron to Cl, so Na+ and Cl- are formed, and then Na+ and Cl- form NaCl through electrostatic action, So NaCl is made up of ions; When HCL is formed, H wants to get an electron to reach a stable structure with two electrons in the outer shell, and Cl also wants to get a stable structure with an electron to reach the outer layer of 8 electrons, both want to get electrons, and can only form compounds HCL by sharing electron pairs, so HCL does not form anions and cations when it is formed, but compounds formed by sharing electron pairs, so HCL is composed of molecules, and the same H2SO4 is also a compound formed by non-metals and non-metals, which is composed of molecules. In general, the compounds formed by metals and non-metals are composed of ions, while the compounds formed by non-metals and non-metals are composed of molecules, for example, MgCl2 is composed of ions, and HnO3 is composed of molecules.

In junior high school, it is generally not required to master these, as long as you memorize a few typical compounds composed of ions, and it is also necessary to point out that there are some substances that are composed of atoms, such as diamond, graphite, etc.

1 Yes. 2. A sodium ion loses an electron to form a sodium ion, a chloride ion gains an electron to form a chloride ion, and sodium ions and chloride ions form sodium chloride under electrostatic action.

Yes. Na+ and Cl- make up NaCl

HCl ionizes in water to form H+ and Cl-

H2SO4 is also an ionic composition.

1. There are 4 substances in a closed container. They react fully under certain conditions, and the mass of each substance before and after the reaction is measured as follows:

Substance x y z q

Pre-reaction mass g 4 6 1 20

The post-reaction mass g 0 6 13 to be measured.

The relative molecular mass of X is known to be n, and the relative molecular mass of q is 2N. Fill in the following blanks accordingly:

1) What is the mass of q after the reaction?

To be measured =4+6+1+20-0-6-13=12

2) What is the ratio of the stoichiometric number of the chemical equation x to q for this reaction?

4-0)/n]:[20-12)/(2n)]=1:1

2. A substance R is burned in pure oxygen to produce and, and the inference for the composition of the substance R is:

1) How many elements are in substance R?

Contains carbon and hydrogen, so the substance R only contains carbon and hydrogen elements.

2) What is the chemical formula of substance R?

The ratio of the number of atoms of substance r containing only carbon and hydrogen is (:4

So the chemical formula of the substance R is CH4

1,。（1）q=12 (2) x:q=1:

1 2.(1) c, h (2) h20 i.e. h atom o atom c in the substance r c:h=1:

4 Chemical formula: CH4

q = 20 + 4-13 = 11, also reactants.

1) The mass of q after the reaction is 11.

2) The ratio of the stoichiometric number of the chemical equation x to q of the chemical equation of the reaction = 2 * 4: 9 = 8: 9.

Medium gram, gram; Contains grams, contains grams, grams + grams = grams.

Therefore: (1) Substance R contains only two elements, C and H.

2）c：h=：:4。The chemical formula of the substance R is CH4

.The overall mass conservation after the reaction is 4+6+1+20-6-13=12 The mass of Q is 12g

X is 4g, q is 8g, and because the relative molecular mass of q is exactly twice that of x, the amount of substances involved in the reaction x and q is the same, and the mass ratio of 1:1 is 1:2

The mass of q after the reaction of 1 (1) is (4+6+1+20)-(0+6+13)=12g

2) x:q=4*n:20*2n=4n:40n=n:10n2 (1) Contains C and H elements.

2）。。No, it won't.

1. (1) The mass of q after the reaction is 12, according to the law of conservation of mass, the mass before and after the reaction remains unchanged, so (4+6+1+20)-(0+6+13)=12

2) The chemical equation of the reaction is that the ratio of the stoichiometric number of x to q is twice the relative molecular mass of 3 and the mass of q is 3 times the mass of x during the reaction, and in order to achieve equilibrium, the ratio of the stoichiometric number of x to q is 3 2.

2. (1) Substance R contains two elements. c and h

2) The chemical formula of the substance R is CH4are converted to mol calculations, and they can be obtained.

1) What is the mass of q after the reaction?

20-m+4=12

m=122) What is the ratio of the stoichiometric number of the chemical equation x to q for this reaction?

nx+mq=z

nn 2mn

nn:2mn=4:12

n:m=2:3

The ratio of the stoichiometric number of x to q is 2:3

2. A substance R is burned in pure oxygen to produce and, and the inference for the composition of the substance R is:

1) How many elements are in substance R?

C-containing mass = H-containing mass =

Therefore, the substance R contains the elements C, H, and O.

2) What is the chemical formula of substance R? Please write out the process.

The ratio of the number of elements containing C, H, and O in substance R is:::16:1 The chemical formula of substance R is C8H16O

1. X decreases after the reaction, so it is a reactant, and Y does not change before and after the reaction, so it is the catalyst Z that increases after the reaction, so it is a product, q=20+4-13=11, which is also a reactant.

1) The mass of q after the reaction is 11.

2) The ratio of the stoichiometric number of the chemical equation x to q of the chemical equation of the reaction = 2 * 4: 9 = 8: 9.

2. Medium grams, grams; Contains grams, contains grams, grams + grams = grams.

Therefore: (1) Substance R contains only two elements, C and H.

2）c：h=：:4。The chemical formula of substance R is CH4, methane.