Question

Assertion :$31.26$ mL of $0.165\text{M}$ solution of $Ba{\left(OH\right)}_2$ is exactly neutralised by $25$ mL of citric acid, $C_6{H}_8{O}_7$ of molarity $0.138$. Reason: The acid is tribasic in nature.

• A. Assertion is correct but Reason is wrong
• B. Assertion is wrong but Reason is correct
• C. Both Assertion and Reason are correct and Reason is correct explanation of Assertion
• D. Both Assertion and Reason are correct but Reason is not correct explanation of Assertion

Answer 1

The correct option is C Both Assertion and Reason are correct and Reason is correct explanation of Assertion

As we know, at equivalence point, all reactants uses same number of equivalents.
Meq. of $Ba{\left(OH\right)}_2$ $=$ Meq. of acid
Let valency of acid be $n$.

Therefore, $31.26\times 0.165\times 2=25\times M\times n=25\times 0.138\times n$
$⟹n=3$
Hence, citric acid is tribasic in nature.