дано
V(C2H2) = 8 L
m(CaC2)-?
CaC2+2H2O-->Ca(OH)2+C2H2
n(C2H2) = V(C2H2) / Vm = 8/22.4 = 0.357 mol
n(CaC2) = n(C2H2) = 0.357 mol
M(CaC2) = 64 g/mol
m(CaC2) = n*M= 0.357 * 64 = 22.85 g
ответ 22.85 г
