Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 20257 AprilEvening Shift
Exam
JEE Main
Year
2025
Date
7 April
Shift
Evening Shift
Subject
Chemistry
Chapter
Ionic Equilibrium

JEE Main 2025 · 7 April · Evening Shift · Chemistry · Ionic Equilibrium

Only litre buffer solution was prepared by adding 0.10 mol each of...

Only litre buffer solution was prepared by adding 0.10 mol each of NH3\mathrm{NH}_3 and NH4Cl\mathrm{NH}_4 \mathrm{Cl} in deionised water. The change in pH on addition of 0.05 mol of HCl to the above solution is ________ ×10−2\times 10^{-2}, (Nearest integer) (Given : pKb\mathrm{pK}_{\mathrm{b}} of NH3=4.745\mathrm{NH}_3=4.745 and log⁡103=0.477\log _{10} 3=0.477)

Correct answer

0

Step-by-step solution

<br/>pOH=pKb+log⁡[NH4+][NH3]<br>pOH=4.745<br/>\begin{aligned}<br />& \mathrm{pOH}=\mathrm{pK}_{\mathrm{b}}+\log \frac{\left[\mathrm{NH}_4^{+}\right]}{\left[\mathrm{NH}_3\right]} \\<br>& \mathbf{p O H}=4.745<br />\end{aligned}
on adding 0.05 mole HCl
<br/><br/>NH3+H⊕→NH4⊕<br>0.10.050.1<br>0.0500.15<br/><br>pOH′=4.745+log⁡3<br>pOH′−pOH=0.477<br>14−pH′−14+pH=0.477<br>ΔpH=0.477<br>=47.7×10−2≈48×10−2<br/>\begin{aligned}<br />& \begin{array}{llll}<br />\mathrm{NH}_3+ & \mathrm{H}^{\oplus} & \rightarrow & \mathrm{NH}_4^{\oplus} \\<br>0.1 & 0.05 & & 0.1 \\<br>0.05 & 0 & & 0.15<br />\end{array} \\<br>& \mathrm{pOH}^{\prime}=4.745+\log 3 \\<br>& \mathrm{pOH}^{\prime}-\mathrm{pOH}=0.477 \\<br>& 14-\mathrm{pH}^{\prime}-14+\mathrm{pH}=0.477 \\<br>& \Delta \mathrm{pH}=0.477 \\<br>& =47.7 \times 10^{-2} \approx 48 \times 10^{-2}<br />\end{aligned}
Practice Ionic Equilibrium on Quantrex Academy →

More from Ionic Equilibrium

Given is a concentrated solution of a weak electrolyte A_xB_y of concentration 'c' and… JEE Main 2026M_3 A_2 is a sparingly soluble salt of molar mass y g mol ^ -1 and solubility x g L ^ -1… JEE Main 2026Arrange the following resultant mixtures in increasing order of their pH values A. 10 mL… JEE Main 202620 mL of a solution of acetic acid required 28.4 mL of 0.1 M NaOH for its neutralization.… JEE Main 2026The pH of a solution obtained by mixing 5 mL of 0.1 M NH_4OH solution with 250 mL of 0.1… JEE Main 2026The first and second ionization constants of a weak dibasic acid H_2 A are 8.1 × 10^ -8… JEE Main 2026At 25°C , 20.0 mL of 0.2 M weak monoprotic acid HX is titrated against 0.2 M NaOH. The pH… JEE Main 2026The solubility product constants of Ag_2CrO_4 and AgBr are 32x and 4y respectively at 298… JEE Main 2026 Full Ionic Equilibrium list All JEE Main PYQs