Question

Using the ideal gas law and stoichiometry calculations, determine the amount of zinc metal needed to produce 150 ml of h2 gas at 293 k via the oxidation reaction below

Answer 1

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