1. дано
V(CH4) = 100 L
----------------------
V(O2)-?
100 X
CH4+2O2-->CO2+2H2O
1mol 2mol
X = 100*2 / 1 = 200 L
ответ 200 л
2.
дано
m(Pb) = 41.4 g
-------------------------
V(H2)-?
X 41.4
PbO2+2H2-->Pb+2H2O M(Pb) = 207 g/mol Vm = 22.4 L/mol
2*22.4 207
X = 44.8*41.4 / 207 = 8.96 L
ответ 8.96 л