дано
V(CO2) = 7.6 L
mppa(Ba(OH)2) = 285 g
W(Ba(OH)2) = 12%
---------------------------
m(BaCO3)-?
m(Ba(OH)2) = 285*12% / 100% = 34.2 g
M(Ba(OH)2) = 171 g/mol
n(Ba(OH)2) = m/M = 34.2 / 171 = 0.2 mol
n(CO2) = V(CO2) / Vm = 7.6 / 22.4 =0.34 mol
n(Ba(OH)2)
Ba(OH)2+CO2-->BaCO3+H2O
n(Ba(OH)2) = n(BaCO3) = 0.2 mol
M(BaCO3) = 197 g/mol
m(BaCO3) = n*M = 0.2*197 = 39.4 g
ответ 39.4 г