Question

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

• A. $HCl$
• B. $HCl{O}_4$
• C. $HN{O}_3$
• D. $H_{3}P{O}_4$

Answer 1

Answer: (D)

$H_{3}P{O}_4$

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 $1N$ $so{l}^n$ from $1$ mole is $1$ litre. $HCl,$ ${HClO}_4$ and ${HNO}_3$ are all monobasic ($n$ factor $1$) , but $H_3{PO}_4$ has basicity value $3$ , it is dibasic in nature. So, it won't give $1N$ solution