JEE Main 2022 · ChemistryMultiple choiceSingle correctMediumCalculation

JEE Main 28 June 2022, Shift 2, Chemistry Q64

Question 64 of 90 in this shift, Chemistry question 4 of 30, Section A.

A student needs to prepare a buffer solution of propanoic acid and its sodium salt with pH 4. The ratio of

\frac{[\mathrm{CH_3CH_2COO^-}]}{[\mathrm{CH_3CH_2COOH}]}

required to make buffer is __________. Given :

\mathrm{K_a(CH_3CH_2COOH)} = 1.3\times10^{-5}

(1)0.03
(2)0.13Official answer
(3)0.23
(4)0.33

Official answer

Option 2

NTA final key.

Chapter: Equilibrium
Topic: pH and Buffers
Idea tested: Acidic Buffer pH Calculation

Same idea in other shifts

Asked 4× in all

4 Apr 2026, Shift 2 · Q5520 mL of a solution of acetic acid required 28.4 mL of 0.1 M NaOH for its neutralization. A solution (X) was prepared by mixing 20 mL of…EasySingle correct
30 Jul 2022, Shift 2 · Q5450 mL of 0.1 M $\mathrm{CH_3COOH}$ is titrated against 0.1 M NaOH solution. When 10 mL of NaOH is added, the pH of the solution becomes…MediumNumerical value
18 Mar 2021, Shift 1 · Q55In order to prepare a buffer solution of pH 5.74, sodium acetate is added to acetic acid. If the concentration of acetic acid in the…EasyNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.