`25 mL` of `0.2M` phosphorus acid `(H_(3)PO_(3))` neutralises exact `80 mL` of a solution containing `10 g NaOH ( 50% "pure") per dm^(3)`. Report basicity of acid and write balanced chemical equation for neutralisation.

Explanation

Meq. of acid`=Meq. of NaOH`
`25xx0.2xxn=(10)/(40)xx(50)/(100)xx80`
`:. N=2`
`:.` Basicity of acid`=2` Neutralisaton reaction:
`2NaOH+H_(3)PO_(3)rarrNa_(2)HPO_(3)+2H_(2)O`