Дано
m(CaCO3) = 50 g
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m(CH3COOH)-?
CaCO3+2CH3COOH-->(CH3COO)2Ca+H2O+CO2
M(CaCO3)= 100 g/mol
n(CaCO3) = m/M = 50 / 100 = 0.5 mol
n(CaCO3)=2n(CH3COOH) n(CH3COOH) =0.5*2 = 1 mol
M(CH3COOH) = 60 g/mol
m(CH3COOH) = n*M =1 * 60 = 60 g
ответ 60 г