Acid anhydride (A) +`underset((CF_(3) "group")) ("Monobasic acid (B)")` `hArr`Monobasic acid(C ) +`underset((Two CF_(3) "group")) ("Anhydride(D)")`
Eq. wt.=128 Eq. wt.=74
Probable formula of acid (B)=`CF_(3)(CH_(2))_(n)COOH`
Equivalent weight of (B) =`("Molecular weight")/("Basicity")`
`128=(57+12+14n+12+32+1)/1`
n=1
`therefore(B)=CF_(3)CH_(2)COOH` and `(D)=(CF_(3)CH_(2)CO)_(2)O`
Similarly, molecular formula of acid (C ) can be calculated to be `CH_(3)CH_(2)COOH`. The reaction, therefore, can be given as,
`underset((A))((CH_(3)CH_(2)CO)_(2)O)+underset((B))(F_(3)"CC"H_(2)COOH)hArrunderset((C ))(CH_(3)CH_(2)COOH)+underset((D))((F_(3)"CC"H_(2)CO)_(2)O)`