Two chemistry problems that I don t know at all, solve

1.To solve this problem, you have to know the movement of the Cl atom before and after the reaction.

KCLO3+6HCl=KCL+3Cl2+3H2OIn fact, CL in KCLO3 gets 6e and becomes KCl, while CL in 6HCl loses 6E and becomes Cl2.

So the formula for the formation of chlorine is 74.

2.The relative density of the gas mixture to hydrogen is , so the average molecular weight of the gas mixture is.

If the gas mixture contains N2O4X, then it contains NO2(1 X), so the average molecular weight is 92X+46(1-X)=

Solve x. That is, the conversion rate of NO2 under this condition is 21%.

, so only 1 part of the chlorine gas generated is 35 parts, and 5 parts are 37, so the formula of chlorine is 2*(35+37*5) 6=

2.The relative density of the gas mixture for hydrogen is, so the formula of the gas mixture is nitrogen dioxide is 46, nitrogen tetroxide is 92, and the conversion rate is x, then 92x+46(1-x)=

The conversion rate is calculated to be 21%.

1.After the trim equation, it can be seen; 3 chlorine molecules are generated, one of which is chlorine-35, and 5 chlorine-37, so its formula is: 1 35 5 37 3 73 33

2 Let the nitrogen dioxide at the beginning be one mole and the conversion rate is x

1－x）＊46＋0．5x＊92／1－0．5x＝2＊27．85x＝34．83％

1.Chlorine gas is prepared by the reaction of potassium chlorate and hydrochloric acid, and the chlorine in potassium chlorate and the chlorine in hydrochloric acid are 1:5, and the formula for generating chlorine gas is.

Let the relative molecular mass of 2a be m, the relative molecular mass of 5b be n, and the relative molecular mass of c and d will be

2a+5b=2c+4d

m...n...9×2...22×4∴m/

m=26 is known from the conservation of mass.

m+n=9×2+22×4

n=80, so in this reaction, the mass ratio of b to d is =5b:4d=n:(22 4)=10:11

Solution: 2a+5b=2c+4d

The ratio of the relative molecular weights of c and d is 9 22

2c∶4d=18：88

It can be obtained by completely reacting with b.

2a∶4d=26∶88

It can be obtained from the law of conservation of mass.

2a+5b=2c+4d

Therefore, the mass ratio of b and d in the reaction is 80:88=10:11 Note: the ratio of the relative molecular mass of C and D is 9 22, not the mass ratio of C and D is 9 22, don't be confused.

Solution: The amount of sodium hydroxide substance n (Naoh) =

Let the mass of magnesium in the alloy be m and the mass of aluminum be y, then 1) x+y=let the amount of sodium hydroxide consumed by magnesium chloride and aluminum chloride respectively a, bmg+2HCl=mgCl2+H2

2al+6hcl=2alcl3+3h2↑

mgcl2 + 2naoh=mg(oh)2↓+2naclx/(24g/mol) a

alcl3 + 3naoh=al(oh)3↓+3nacly/(27g/mol) b

a+b=a=2x/(24g/mol),b=3y/(27g/mol)2) x/(12g/mol)+y/(9g/mol)=3x+4y=

3x+3y=

1), 2) Equation synthesis, obtained, x=, y=

Percentage of magnesium in the original alloy =

The amount of magnesium in the substance n (mg) =

The amount of the substance of aluminum, n(al)=

mg---mgcl---mg(oh)2

al---alcl3---al(oh)3

When the precipitation amount is maximum, the precipitated components are magnesium hydroxide and aluminum hydroxide.

The mass of magnesium hydroxide formed m[mg(oh)2]=

The mass m[Al(OH)3] = of the aluminium hydroxide is generated

Mass max = of the mass generated from the precipitate

A: 1The maximum value for generating precipitate is.

2.Percentage of magnesium in the original alloy =

The gram alloy is dissolved in hydrochloric acid to generate aluminum chloride and magnesium chloride with a volume of 400ml. When 1m of sodium hydroxide is added, when the precipitation amount is maximum, magnesium ions are fully converted into magnesium hydroxide, and aluminum ions are converted into aluminum hydroxide, and aluminum hydroxide is not dissolved by sodium hydroxide. At this time, the volume is twice as large, and 400ml of sodium hydroxide is added.

Sodium dehydroxide is used for the reaction, let magnesium be xg, aluminum is 3 9-xg, find the number of ion moles, x 24mol and (, known [(x 24)*2+(, find x, which is the mass of magnesium element. The maximum precipitation value is calculated based on the conversion of magnesium and aluminum to hydroxides. I don't know how to ask again.

The chemical formulas of the chemical formulas represent the results of inference: a caco3, c cao , c co2 , d ca(oh)2 , e c , f co , g cuo , q cu , l cacl2

Pure experience!

18o refers to an oxygen atom with a mass of 18. The atomic number of oxygen is 8, and the number of protons is also 8. If the mass number is 18, then the number of neutrons = the number of masses - the number of protons = 18-8 = 10.

d refers to the hydrogen atom with mass number 2. The atomic number of hydrogen is 1, and the number of protons is 1. If the mass number is 2, then the number of neutrons = the number of masses - the number of protons = 2-1 = 1.

The H218O molecule is formed by combining two hydrogen atoms with a mass of 1 (neutron number = mass number - proton number = 1-1 = 0) and 1 oxygen atom with a mass of 18 (neutron number 10), and the neutron number in the molecule is 10.

The D2O molecule is formed by combining two hydrogen atoms with a mass of 2 (neutron number 1) and an oxygen atom with a mass of 16 (neutron number = mass number - proton number = 16-8 = 8), and the neutron number in the molecule is 10.

Answer: c.

The type of element determines the number of protons, and then determines the number of neutrons according to the mass number, and the number of neutrons in the H218O and D2O molecules in this question is 10, so C is chosen.

H has only protons, d has one neutron, one proton, O18 has 8 protons, 10 neutrons, O16 has 8 protons, 8 neutrons, so the answer is c. Amount.

c equals.

There are no neutrons in H, and there are 10 neutrons in 18O, so there are a total of 10 neutrons in H218O; There is one neutron in D, there are 8 neutrons in O, so there are also 10 neutrons in D2O, so the answer is C

Contains in 1L.

g, then the concentration is.

The volume of spring water containing 1 mol of magnesium ions is: 1 (2*10 -3) = 106g

Na2CO3 is exactly 1mol, strictly speaking, the concentration of these two solutions is not the same.

Because after dissolving a 106g solid in 1L of water, the volume is no longer 1L, so the concentration is not 1mol L

The second concentration is first dissolved in water, and then diluted to 1L, then the concentration is just 1mol L, and the reaction formula is written incorrectly:

2co+o2=2co2

CO2 is formed by the complete reaction

Also, the amount of matter is.

The number of molecules contained is:

Piece. Hope it helps.

1) From the inscription, the mass of CO2 generated is 100+ grams, CaCO3+2HCl==CaCl2+H2O+CO2

The column formula can be found as (100 44) = (x x = 10 The mass of calcium carbonate participating in the reaction is 10 grams.

2) (44 73) = ( y= The mass fraction of solute in dilute hydrochloric acid is .

According to the title, it can be found that the mass before and after the reaction is reduced, and then look at the reaction process, only carbon dioxide gas is generated, so the reduced mass is the mass of carbon dioxide, which is 100+, according to CaCO3+2HCl==CaCl2+H2O+CO2, the mass of calcium carbonate can be obtained as 10g, and the mass of hydrochloric acid of the reaction is, so the mass fraction of hydrochloric acid is:

Solution: Let the mass of calcium carbonate participating in the reaction be xg

The mass of dilute hydrochloric acid participating in the reaction is yg

The total mass of the substance in the beaker before the reaction is 112g

The total mass of the remaining material in the beaker after the reaction is.

The mass generated by the reaction is.

cac03+2hcl=cacl2+co2↑+h2ox y

100/44=x/ x=10g

73/44=y/ y=

The mass fraction of the solute in dilute hydrochloric acid is thank you

Because impurities do not react with acids, it is the CO2 emitted by the reaction of calcium carbonate in limestone with hydrochloric acid that causes the total mass to decrease

The total mass before the reaction is 112g, and the total mass after the reaction Therefore, the mass of CO2 generated is set to be the mass of calcium carbonate participating in the reaction is X, and the mass of HCl participating in the reaction is Y.

caco3+2hcl==cacl2+co2↑x y

x=y=mass fraction of solute in dilute hydrochloric acid is.

A: ···

1. The reactants are 112g in total, and the products are weightless. Because impurities are insoluble in water and do not react with acids, weight loss is all CO2 generation.

2. Limestone (CaCO3) reacts with acid, 1 CaCO3 —1 CO2=x—, x=10g.

3. Solute (CaCl2) Y —CaCO3 = Y - 10g, so Y =. Mass Score = .