дано
m техн(FeS) =2000 g
W(прм) =10%
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V(H2S)-?
m чист (FeS) = 2000 - (2000 *10% / 100%) =1800g
FeS+2HCL-->FeCL2+H2S
M(FeS) = 88 g/mol
n(FeS) = m/M = 1800 / 88 = 20.45 moL
n(FeS) = n(H2S) = 20.45 mol
V(H2S) = n*Vm = 20.45 *22.4 = 458.08 L
ответ 458.08 л