1)
дано
m(CH4) = 3.2 g
----------------------
V(O2)-?
CH4+2O2-->CO2+2H2O
M(CH4) = 16 g/mol
n(CH4) = m/M = 3.2 / 16 = 0.2 mol
n(CH4) = 2n(O2) , n(O2) = 0.2*2 = 0.4 mol
V(O2) = n*Vm = 0.4 * 22.4 = 8.96 L
ответ 8.96 л
2)
дано
m(Zn) = 6.5 g
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V(H2)-?
Zn+2HCL-->ZnCL2+H2
M(Zn) = 65 g/mol
n(Zn) = m/M = 6.5 /65 = 0.1 mol
n(Zn) = n(H2) = 0.1 mol
V(H2) = n*Vm = 0.1 * 22.4 = 2.24 L
ответ 2.24 л