Question

On reaction complete with an acid 12 gram of mg giving a creating volume of hydrogen gas what would be the volume of the gas at stp

Answer 1

Mg + 2HCl = MgCl2 + H2
So One mole of Mg reacts with 2 moles of H2 and gives 1 mole of H2

Now, as atomic weight of Mg=24, no. of moles of Mg present = 0.5
as 1 mole of Mg reacts with 2 moles of HCl to give 1 mole H2
0.5 moles of Mg will react with 1 mole of HCl to give 0.5 moles of H2