Дано
m(HCOH)=120 g
m(C2H5OH)=92 g
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m(HCOC2H5)-?
120 92 X
HCOH+C2H5OH-->HCOC2H5+H2O
46 58
M(HCOH)=30 g/mol
M(C2H5OH)=46 g/mol
M(HCOC2H5)=58 g/mol
n(HCOH)=m/M=120/30=4 mol
n(C2H5OH)=92/46=2 mol
n(HCOH)>n(C2H5OH)
92/46 = X/58
X=116 g
ответ 116 г