a) \(n_{NaOH}=0,05.0,2=0,01\left(mol\right)\)
PTHH: CnH2n+1COOH + NaOH --> CnH2n+1COONa + H2O
0,01<-----------0,01
=> \(M_{C_nH_{2n+1}COOH}=\dfrac{0,74}{0,01}=74\left(g/mol\right)\)
=> n = 2
=> CTPT: C2H5COOH
CTCT: \(CH_3-CH_2-COOH\)
b)
\(n_{C_2H_5COOH\left(pư\right)}=\dfrac{0,01.70}{100}=0,007\left(mol\right)\)
PTHH: C2H5COOH + C2H5OH --H+,to--> C2H5COOC2H5 + H2O
0,007--------------------------->0,007
=> \(m_{C_2H_5COOC_2H_5}=0,007.102=0,714\left(g\right)\)