You did not include the reaction.
This reaction meets the statement:
Zn + 2 HCl ---> ZnCl2 + H2(g)
So, I am going to show you how to solve the problem ,from that reaction.
Data:
Zn =?
V = 150 ml
T = 293 k
I also have to assume atmospheric pressure, p = 1 atm
1) Determine the number of moles of H2 gas, using ideal gas law.
pV = nRT => n = pV / RT = 1 atm * 0,150 liter / (0,0821 atm*liter/K*mol * 293 k)
=> n = 0,0062 mol H2
2) State the molar ratios from the reaction:
1 mol Zn : 1 mol H2
3) State the proportion with 0,0062 mol H2
1 mol Zn / 1 mol H2 = x mol Zn / 0,0062 mol H2 =>
x = 0,0062 mol Zn
4) Determine the mass of Zn using the atomic mass of Zn: 65.39 g/mol
=> mass of Zn = 0,0062 mol * 65,39 g / mol = 0,41 g
Answer: 0,41 g
