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Na mg AL reacts with HCl to produce hydrogen mainly depending on his reaction process.

Na reacts with hydrochloric acid, mainly with HCl and H2O, and finally produces hydrogen, because Na can only lose one electron, that is, it takes two Na to get a hydrogen molecule, Na=1 2H2

In the same way, 1 mg can produce H2, 2AL=3H2

1) Because it is the amount of equal substance, na:mg:al=1 2:1: 3 2=1:2:3

Too lazy to type, and the same goes after that.

2) Because it is equal mass, that is, al is made into equal mass, 1 11:2 12:3 13, and the increment is less hydrogen than the mass of the metal: 10:11:12

3) To have equal dissolved masses, the reciprocal ratio of the amount of NaCl, MgCl2, Al2Cl3 substances.

4) Because aluminum gains and loses more electrons, it must be aluminum if there is a surplus.

2na+2hcl=2nacl+h2

2mg+4hcl=2mgcl2+2h2

2al+6hcl=2alcl3+3h2 So it's 1:2:3 In short, the method is like this, and the following questions are basically like this

It is to convert the stoichiometric into the requirements of the question

CO2 sulfur dioxide is dissolved in water to form sulfurous acid, which is a weak acid and cannot react with barium chloride (strong acid to weak acid).

NH3 and sulfurous acid form salts, which can be precipitated with barium chloride to form barium sulfite.

H2S reacts with sulfur dioxide to form sulfur elemental precipitates.

NO2 oxidizes sulfurous acid to sulfuric acid, because sulfuric acid and hydrochloric acid are both strong acids, so sulfuric acid can form barium sulfate precipitate with barium chloride.

CO2 cannot.

Hope it helps.

co2.。。Obviously, it doesn't produce baso4... It just doesn't oxidize 4-valent S to 6-valent.

H2S + H2SO4 (concentrated) = S + SO2 + 2H2OH2S The product is S -2 valence becomes 0 valence.

The product of H2SO4 is that the +6 valence of SO2 becomes +4 valence.

The valencies are close but not crossed.

Instead of. H2S generates a so2 -2 valence that becomes a +4 valence.

H2SO4 generates a price of S+6 and becomes a price of 0.

That is to say, the reaction of different valence states of the same element must be close to the center, for example: trivalent iron and iron element react to form divalent iron, but will not generate iron lower than 0 or higher than trivalent, this is because the redox reaction of the same element must be a valence state as an oxidant to be reduced, a valence state as a reducing agent to be oxidized, and the reaction price state must be in the center. They don't cross across two valences that react on their own!

That is, they can only be close to the same valence, and cannot be cross-priced.

For example, sulfur has -2 valence and +4 valence, and in chemical reactions, -2 valent sulfur and +4 valence sulfur can become 0 valence, but -2 valent sulfur and +4 valence sulfur cannot become +2 and 0 valence respectively, which is called cross-valence. If you don't understand, you can ask me again.

For example, there is a valency of s.

If the sulfur has a -2 valence and a +4 valence in a reaction, then the -2 valence can only become 0 valence, (but not +4 valence) and the +6 valence can only become +4 valence (but not 0 valence).

I just learned, that's what the teacher said, I think it's easy to understand, you can try it!

H2S+H2SO4 (concentrated) S+SO2 +2H2O

The S explicit -2 valence in H2S can only become a zero-valent sulfur element, and cannot be turned into a +4 valence in SO2 across rows. In the same way, the other pair can only change like that.

It is a chemical reaction of the same element, that is, the disproportionation reaction, and the valency is close to the intermediate valence state. For example, under certain conditions, +5 valence chloride ions and -1 valence chloride ions will produce 0-valent chlorine gas, but not +7-valent or -1 valent chloride ions. This is related to the redox capacity of the ions.

In general, the coercion is weak, and the redox capacity of different valence states is different.

You'll know it after reading the competition book.

If a redox reaction occurs between different valence states of the same element, the valency of the element can only be close to each other, and there is no crossing. For example, sulfur dioxide and hydrogen sulfide react to form sulfur element, in which the sulfur element in the sulfur dioxide changes from +4 valence to 0 valence, and the sulfur element in hydrogen sulfide changes from -2 valence to 0 valence.

are close to 0 prices.

Because sodium bicarbonate is relatively unstable, it is easy to decompose when heated.

2nahco3=na2co3+h2o+co2168 106 18 44

The reduced mass is the carbon dioxide and water vapor generated δm=g so n(NaHCO3)=2*

So m(NaHCO3) = m(Na2CO3) = Hope it will be helpful to your chemistry Please adopt it in time.

Solution: Let the mass of NaHCO3 be X

2nahco3=na2co3+co2+h2o2*84 106

x m（na2co3）m（na2co3）=106x/(2*84)（38-x)+106x/(2*84)=

I don't have a pen on hand, so I won't help you calculate. Solve x is the mass of NaHCO3 and 38-x is the weight.

Due to the good thermal stability of sodium carbonate, it will not decompose when burned in the air; Sodium bicarbonate is burned and decomposed into sodium carbonate, water and carbon dioxide;

Therefore, all grams are sodium carbonate.

2NaHCO3==Na2CO3 + CO2 (gas) + H2O (burning gasification) is known by the question Substances are reduced in grams, so carbon dioxide and water are each reduced, so sodium bicarbonate has a mass of grams.

The mass of sodium carbonate is grams.

Using sodium equilibrium, two equations can be found with two unknowns.