md 216 g
CH3CH=O + Ag2O => CH3COOH + 2Ag
44 2x108
=> md = 44x216/2x108 = 44 g etanal
=>
la 200 g sol ...................... 44 g etanal
la 300 g ............................ a = 66 g etanal
=> ms = 300 g
md = 66 g
stim ca c% = mdx100/ms = 66x100/300
= 22%