Question

Assertion: A 0.2M solution of carbonic acid is a weaker conductor of electricity than a 0.2M solution of $HBr$.

Reason: In solutions with the same concentration of solute molecules, $H_{2}C{O}_3$ is less dissociated than $HBr$.

• A. The Assertion and Reason are correct and Reason is the correct explanation of Assertion
• B. Both the Assertion and Reason are correct and Reason is NOT the correct explanation of Assertion
• C. The Assertion is correct but Reason is not correct
• D. The Assertion is not correct but Reason is correct
• E. Both the Assertion and Reason are not correct

Answer 1

Answer: (A)

The Assertion and Reason are correct and Reason is the correct explanation of Assertion

Option A is the correct answer.

$HBr$ dissociates completely in a solution forming $H^{+}$ and ${Br}^{-}$ ions. Whereas, $H_{2}C{O}_3$ partially dissociates in a solution forming $H^{+}$ and ${HCO}_3^{-}$ ions. Thus in the same concentration of both the acids $HBr$ is a stronger acid than $H_{2}C{O}_3$.

As $HBr$ dissociates completely, $H^{+}$ ion concentration is more in this case, and hence $HBr$ is a good conductor of electricity.