`a)`

Acid: `C_nH_{2n}O_2`

`n_{CO_2}={13,44}/{22,4}=0,6(mol)`

BTNT C: `n_A={n_{CO_2}}/n={0,6}/n(mol)`

`->M_A=14n+32={14,8}/{{0,6}/n}={74}/{3}n`

`->n=3`

`->A:C_3H_6O_2`

CTCT: `CH_3-CH_2-COOH`

`b)`

`n_{H_2}={4,48}/{22,4}=0,2(mol)`

`C_2H_5COOH+Na->C_2H_5OONa+1/2H_2`

`CH_3COOH+Na->CH_3COONa+1/2H_2`

Theo pt:

`n_{Na}=2n_{H_2}=0,4(mol)`

BTKL: `m=25,4+0,4.23-0,2.2=34,2(g)`