To neutralise completely 20 mL of 0.1M aqueous solution of phosphorus acid (H_3PO_3), the volume of 0.1 M aqueous KOH solution required will be ?

To neutralise completely 20 mL of 0.1M aqueous solution of phosphorus

1.	To neutralise completely 20 mL of 0.1M aqueous solution of phosphorus acid (H_3PO_3), the volume of 0.1 M aqueous KOH solution required will be ?
Answer» 10 mL 20 mL 40 mL 60 mL Solution :`H_(3)PO_(3)` is a dibasic acid and ionises as follows: `H_(3)PO_(3) 2-)` KOH is a monoacid base. Hence, 0.1 M KOH = 0.1 N KOH `0.1 M H_(3)PO_(3) = 0.2 N H_(3)PO_(3)` `underset(KOH)(N_(1)V_(1)) = underset(H_(3)PO_(3))(N_(2)V_(2))` `0.1 XX V_(1) = 0.2 xx 20` or `V_(1) = 40 mL`