Search any question & find its solution
Question:
Answered & Verified by Expert
Aqueous solution of $\mathrm{HNO}_{3}, \mathrm{KOH}, \mathrm{CH}_{3} \mathrm{COOH}$ and $\mathrm{CH}_{3} \mathrm{COONa}$ of identical concentration are provided. The pair (s) of solutions which form a buffer upon mixing is (are)
Options:
Solution:
1836 Upvotes
Verified Answer
The correct answers are:
$\mathrm{HNO}_{3}$ and $\mathrm{CH}_{3} \mathrm{COONa}$, $\mathrm{CH}_{3} \mathrm{COOH}$ and $\mathrm{CH}_{3} \mathrm{COONa}$
A Weak acid and its salt with a strong base forms a buffer.$\therefore$ (D)
$\mathrm{HNO}_{3}$ being a strong acid, displaces weaker acid $\mathrm{CH}_{3} \mathrm{COOH}$.
$\mathrm{HNO}_{3}+\mathrm{CH}_{3}-\mathrm{COO}^{-} \rightleftharpoons \mathrm{CH}_{3}-\mathrm{COOH}+\mathrm{NO}_{3}^{-}$
If $\left[\mathrm{CH}_{3} \mathrm{COO}^{-}\right]>\left[\mathrm{HNO}_{3}\right]$, then solution contains weak acid $\left(\mathrm{CH}_{3} \mathrm{COOH}\right)$ and its conjugate base $\left(\mathrm{CH}_{3} \mathrm{COO}^{-}\right) . \quad \therefore(\mathrm{C})$
$\mathrm{HNO}_{3}$ being a strong acid, displaces weaker acid $\mathrm{CH}_{3} \mathrm{COOH}$.
$\mathrm{HNO}_{3}+\mathrm{CH}_{3}-\mathrm{COO}^{-} \rightleftharpoons \mathrm{CH}_{3}-\mathrm{COOH}+\mathrm{NO}_{3}^{-}$
If $\left[\mathrm{CH}_{3} \mathrm{COO}^{-}\right]>\left[\mathrm{HNO}_{3}\right]$, then solution contains weak acid $\left(\mathrm{CH}_{3} \mathrm{COOH}\right)$ and its conjugate base $\left(\mathrm{CH}_{3} \mathrm{COO}^{-}\right) . \quad \therefore(\mathrm{C})$
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.