дано
m(ppa ZnSO4) = 164 г
W(ZnSO4) = 15%
H2S
---------------------------
V(H2S)-?
m(ZnSO4) = 164*15% / 100% = 24.75g
ZnSO4+H2S-->ZnS↓+H2SO4
M(ZnSO4) = 161 g/mol
n(ZnSO4) = m/M = 24.75 / 161 = 0.154 mol
n(ZnSO4) = n(H2S) = 0.154 mol
Vm = 22.4 L/mol
V(H2S) = n*Vm = 0.154*22.4 = 3.45 L
ответ 3.45 л