\(NaOH+HCOOC_2H_3\rightarrow CH_3CHO+HCOONa\)
_________0,055 __________0,055_________________
\(2AgNO_3+CH_3CHO+H_2O+3NH_3\rightarrow2Ag+2NH_4NO_3+CH_3COONH_4\)
___________0,055 _______________________0,11______________
\(n_{HCOOC_2H_3}=\frac{3,96}{72}=0,055\left(mol\right)\)
\(\rightarrow m=0,11.108=11,88\left(g\right)\)