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Statement-1. The pK(a) of a weak acid be...

Statement-1. The `pK_(a)` of a weak acid becomes equal to pH of the solution at the mid-point of its titration.
Statement-2. The molar concentrations of proton acceptor and proton donor become equal at mid point of a weak acid.

A

Statement-1 is True, Statement-2 is True , Statement-2 is the correct explanation of Statement - 1 .

B

Statement-1 is True, Statement - 2 is True , Statement-2 is NOT a correct explanation for Statement-1.

C

Statement-1 is True, Statement-2 is False.

D

Statement-1 is False, Statement-2 is True.

Text Solution

Verified by Experts

The correct Answer is:
A
Statement-2 is the correct explanation of statement -1, because `pH = pK_(a) +log.(["Salt"])/(["Acid"])`.
At mid poind, [Salt] = [Acid].
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Knowledge Check

  • Assertion (A): pK_(a) of a weak acid become equal of the pH of the solution at the mid-point of titration. Reason (R) : The molar concentration of the proton donor an proton acceptor beomes equal at the mid-point.

    A
    If both (A) and (R) are correc, and (R) is the correct explanation of (A).
    B
    If both (A) and (R) are correct but (R) is not the correct explanation of (A).
    C
    If (A) is correct, but (R) is incorrect.
    D
    If (A) is incorrect, but (R) is correct.

  • The PK_(a) of a weak acid is 5.85. The concentrations of the acid and its conjugate base are equal at a pH of -

    A
    `6.85`
    B
    `5.85`
    C
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    D
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  • Statement 1 : The molar concentrations of proton aceeptor and proton donor become equal at the midpoint of titration of a weak acid. Statement 2 : The pK_(a) of a weak acid becomes equal to pH of the solution at the midpoint of its titration.

    A
    Statement 1 is true, statement 2 is true , statement 2 is correct explanation for statement 3
    B
    Statement 1 is true, statement 2 is true , statement 2 is not a correct explanation for statement 3
    C
    Statement 1 is true, statement 2 is false
    D
    Statement 1 is false, statement 2 is true

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