It is known that 1mol of metal a, 1mol of metal B and 1mol of metal C reacts with enough dilute sulfuric acid to produce 0.5mol of chlorine gas, and the molar ratio of hydrogen is 1:2:3

It is known that 1mol of metal a, 1mol of metal B and 1mol of metal C reacts with enough dilute sulfuric acid to produce 0.5mol of chlorine gas, and the molar ratio of hydrogen is 1:2:3

1mol of metal a reacts with acid to produce 0.5mol of chlorine. According to the conservation of electron gain and loss, the valence of metal A is + 1. 1mol of metal a, 1 mol of metal B and 1 mol of metal C reacts with enough dilute sulfuric acid to produce 1:2:3 of hydrogen. That is to say, the ratio of valence is 1:2:3. Then the valence of metal B and 3 are + 2 and + 3 respectively

Why is the ratio of the amount of hydrogen produced by the reaction of the same amount of metal and sufficient amount of acid equal to the ratio of the valence of the corresponding metal after the reaction?
Please prove and analyze
I'm a freshman in high school, and chemistry is not very good

This is a substitution reaction. If the metal is monovalent, two atoms of the metal element can replace two hydrogen atoms, that is, a hydrogen molecule. If the metal is divalent, one atom of the metal element can replace two hydrogen atoms, that is, a hydrogen molecule. So it's like this

If a metal reacts with an acid to produce an equal amount of hydrogen, the ratio of the amount of the required metal is equal to the reciprocal ratio of the valence of the corresponding metal after the reaction,
Can you give me one or two examples in detail?

3Zn + 6HCl = 3ZnCl2 + 3H2 2Al + 6HCl = 2AlCl3 + 3H2
N (Zn): n (AL) = 2:3 = valence of Zn: valence of Al = 2:3
Its principle is: use the law of electron conservation before and after chemical reaction
If the same amount of hydrogen is produced, the number of electrons obtained by hydrogen is the same in the two chemical reactions, and the number of electrons lost by the metals with the same reaction force is the same. Here, the number of electrons lost by zinc and aluminum is the same. We know that the valence of metals corresponds to the number of electrons lost, that is, the valence of n (Zn) * zinc = the valence of n (AL) * aluminum
So n (Zn): n (AL) = the valence of aluminum: the valence of zinc, the literal expression of the equation is: the ratio of the amount of metal substances is equal to the reciprocal ratio of the valence of the corresponding metal after reaction