Answer:
d. 380g
Step-by-step explanation:
The reaction of production of hydrogen from zinc and HCl is:
Zn + 2HCl → ZnCl₂ + H₂(g)
At STP (1atm of pressure and 273.15K), 112L are:
n = PV /RT
n = 1atm×112L / 0.082atmL/molK×273.15K
n = 5.00 moles
That means you need to produce 5.00 moles of hydrogen. Based on the reaction, 1 mole of Zn produce 1 mole of H₂(g), as yield of reaction is 85%:
5.00 moles H₂(g) ≡ 5.00 moles of Zn / 85% = 5.88 moles of Zn you need
As molar mass of Zn is 65.38 g/mol:
5.88 moles Zn × (65.38g /mol) = 384 g of Zn ≡ d. 380g
I hope it helps!