Дано
m((CH3COO)2Mg)=284 g
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m(CH3COOH)-?
m(Mg(OH)2)-?
X Y 284
Mg(OH)2+2CH3COOH-->(CH3COO)2Mg+2H2O
58 2*60 142
M(Mg(OH)2)=58 g/mol
M(CH3COOH)=60 g/mol
M(CH3COO)2Mg=142 g/mol
X=68*284 / 142=136 g
Y=120*284 / 142=240 g
ответ 136 г, 240 г