дано
m(PbS) = 25 g
η(SO2) = 77%
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V практ (SO2)-?
2PbS+3O2-->2PbO+2SO2
M(PbS) = 207+32 = 239 g/mol
n(PbS) = m/M = 25 / 239 = 0.1 mol
2n(PbS) = 2n(SO2) = 0.1 mol
V теор (SO2) = n*Vm = 0.1 * 22.4 = 2.24 l
V практ(SO2) = 2.24 * 77% / 100% = 1.72 L
ответ 1.72 л
2CH3OH + 3O2 -->2CO2 + 4H2O
2 MeSO4 + 2 H2O =2 Me + O2 + 2H2SO4
1) n(H2SO4) = 12,25/98 = 0,125 моль
2) n(Me) = n(H2SO4) = 0,125 моль
3) M(Me) = m(Me) / n(Me) 8 / 0,125= 64 г/моль Ответ: Cu