The pH of a solution obtained by mixing $5$ mL of $0.1$ M $\mathrm{NH_4OH}$ solution with $250$ mL of $0.1$ M $\mathrm{NH_4Cl}$ solution is ______ $\times10^{-2}$. (Nearest integer) Given: $\mathrm{p}K_b\ (\mathrm{NH_4OH})=4.74$ $\log 2=0.30$ $\log 3=0.48$ $\log 5=0.70$

JEE Main 2026 · ChemistryNumerical answerNumerical valueMediumCalculation

JEE Main 4 April 2026, Shift 1, Chemistry Q74

Question 74 of 75 in this shift, Chemistry question 24 of 25, Section B.

The pH of a solution obtained by mixing

5

mL of

0.1

\mathrm{NH_4OH}

solution with

250

mL of

0.1

\mathrm{NH_4Cl}

solution is ______

\times10^{-2}

. (Nearest integer) Given:

\mathrm{p}K_b\ (\mathrm{NH_4OH})=4.74

\log 2=0.30

\log 3=0.48

\log 5=0.70

Official answer

756

NTA final key.

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

Same idea in other shifts

Asked 3× in all

26 Jul 2022, Shift 2 · Q63Class XII students were asked to prepare one litre of buffer solution of pH 8.26 by their Chemistry teacher. The amount of ammonium…MediumSingle correct
26 Aug 2021, Shift 1 · Q55The $\mathrm{OH^-}$ concentration in a mixture of 5.0 mL of 0.0504 M $\mathrm{NH_4Cl}$ and 2 mL of 0.0210 M $\mathrm{NH_3}$ solution is…MediumNumerical 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.