Question

On dissolving 1 mole of each the following acids, in 1 litre water, the acid which does not give a solution of strength 1 N

• A. Hydrochloric acid
• B. Perchloric acid
• C. Nitric acid
• D. Phosphoric acid

Answer 1

The correct option is D Phosphoric acid

• $1$ mole of acid dissolved in one-litre water will give$1N$ solution only if the acids have basicity value or $n$ factor equals to $1$ In other words if the acid is monobasic then it will give $1N$ solution from $1$mole is $1$ litre.
• $HCl,HCl{O}_4,HN{O}_3$ are all monobasic ($nfactor=1)$, but phosphoric acid i.e. $H_{3}P{O}_4$​ has basicity value $3$ , it is tribasic in nature. So, it won't give $1N$ solution.