Question

A dibasic acid containing C,H and O was found to contain C=26.7% and H=2.2%.The vapour density of dienthyl ester was found to be 73. What is Molecular formula of acid ?
A. `CH_(2)O_(2)`
B. `C_(2)H_(2)O_(4)`
C. `C_(3)H_(3)O_(4)`
D. `C_(4)H_(4)O_(4)`

Answer 1

Correct Answer - B

E.F.Mass =12+1+32=45
VD of ester =73
Mol. Mass of ester `=2xx73=146`
Mol. Mass of acid =Mol. Mass of ester
`-2 xx` Mol, Mass of `C_(2)H_(5)+2xx At.` mass of H
`=146-2xx29+2`
`=146-58+2=90`
`n=("Mol.mass" )/("EF mass") or n =90/45=2 `
`therefore "Mol Formula" = 2xxCHO_(2)=C_(2)H_(2)O_(4).`