дано
m(ppa HCL) = 50 g
W(HCL) = 20%
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m(CaCL2)-?
m(HCL) = 50 * 20% / 100% = 10 g
CaO+2HCL-->CaCL2+H2O
M(HCL) = 36,5 g/mol
n(HCL) = m/M = 10 /36.5 = 0.27 mol
2n(HCL) = n(CaCL2)
n(CaCL2) = 0.27 / 2 = 0.135 mol
M(CaCL2) = 111 g/mol
m(CaCL2) = n*M = 0.135 * 111 = 14.985 g
ответ 14.985 г