If `0.228 g` of silver salt of dibasic acid gabe a residue of `0.162 g` of silver on ignition then molecular weight of the acid is

Options

A. 70
B. 80
C. 90
D. 100

Answer

c

Explanation

Mass of silver salt taken`=0.228 gm`
Mass of silver left`=0.162 gm`
Basicity of acid `=2`
Step`1-` To calculate the equivalent mass of silver salt `(E)`
`=(E)/(108)=(0.228)/(0.162)=E=(0.228)/(0.162)xx108`
`=1529`(Eq. mass o f silver salt `)`
Step`2-` To calculate the eq. mass of acid.
Eq. mass of acid `-` Eq. mass of silver salt`-`Eq. mass of `Ag+` Basicity
`=152-108+1=152-109`
`=43(` Eq. mass of acid `)`
Step`3-` To determine the molecular mass of acid.
Mol. mass of acid `=` Eq. mass of acid `xx` basicity
`=45 x2=90`.