Question

In the reaction, $H_{3}P{O}_4+Ca(OH{)}_2\to CaHP{O}_4+2H_{2}O$, the equivalent weight of phosphoric acid is:

• A. $98$
• B. $49$
• C. $24.5$
• D. $32.67$

Answer 1

Answer: (B)

$49$

$2O{H}^{-}$ ions from $Ca(OH{)}_2$ react with $2H^{+}$ ions given by $H_{3}P{O}_4$.

Therefore, in this reaction basicity of the acid is 2.

Hence, $Eq.wt=\frac{Mol.wt}{2}=\frac{98}{2}=49$

Hence, option B is correct.