Answer:
The volume of H₂ (g) obtained is 22.4L
Explanation:
First of all, think the reaction:
2HCl (aq) + Zn (s) → ZnCl₂ (aq) + H₂ (g)
You have to add a 2, in the HCl to get ballanced.
Now we should know how many moles of each reactant, do we have.
Volume . Molarity = moles
Notice that volume is in mL, so I must convert to L.
275 mL = 0.275L
0.275L . 0.725mol/L = 0.2 moles of HCl
Molar mass of Zn: 65.41 g/m
50 g / 65.41 g/m = 0.764 moles
Ratio between reactants is 2:1, so I need the double of moles of HCl to react, and a half moles of Zn to react.
My limiting reactant is the HCl, for 0.764 moles of Zinc, I need 1.528 (0.764 .2) of HCl, and I only have 0.2 moles.
Ratio between HCl and H₂ is 1:1, so 0.2 HCl make 0.2 moles of gas
Now apply the Ideal Gas Law, to find out the volume
P. V = n . R . T
2 atm . V = 0.2 mol . 0.08206L atm/K mol . 273K
V = (0.2 mol . 0.08206L atm/K mol . 273K ) / 2 atm
V = 2.24 L
