6.0 gm of silver salt of a tetrabasic acid gives 4.32 gm silver on strong heating. The molar mass of the acid is : (Ag = 108)

$\underset{6 \mathrm{gm}}{{\mathrm{Ag}}_4\mathrm{A}}⟶\underset{4.32 \mathrm{gm}}{\mathrm{Ag}}$

POAC on Ag atom
mole of $\mathrm{Ag}$ atom in ${\mathrm{Ag}}_4\mathrm{A}$ = mole of $\mathrm{Ag}$ in Product

 $4\times$ mole of ${\mathrm{Ag}}_4\mathrm{A}$=  mole of $\mathrm{Ag}$

$4\times \frac{6}{4\times 108+A}=\frac{4.32}{108}$

$24\times 25=432+A$

$\mathrm{A}=168 \mathrm{gm}$

$4\mathrm{H}+\mathrm{A}=172\mathrm{gm}$