$nNaOH$ tac dung voi axit =$\frac {7*200}{56*1000}=0,025 mol$Dat $nNaOH=3x$ phan ung voi este
Tang giam khoi luong
cu 1 mol este phan ung khoi luong tang 23*3-41=28 g $C_3H_5(OOCR)_3-> 3RCOONa$
x mol 28x
cu 1 mol axit phan ung khoi luong tang 23-1-22g $RCOOH->RCOONa$
$x*28=207,55-200-0,025*22$
Vay $nNaOH=3x+0,025=0,775$