Question

The volume of $1.5$ M $H_{3}P{O}_4$ solution required to neutralize exactly $90$ mL of a $0.5$ M $Be(OH{)}_2$ solution is:

• A. $10$ mL
• B. $30$ mL
• C. $20$ mL
• D. $60$ mL

Answer 1

The correct option is C $20$ mL

For the completion of a chemical reaction, the gram equivalent should be same-

Gram Equivalent $H_{3}P{O}_4$ = Gram equivalent $Be(OH{)}_2$

So $N_1\times V_1=N_2\times V_2$

$4.5\times V_1=1\times 90=20ml$