40 mL of 0.1 M ammonia solution is mixed with 20 mL of 0.1 M HCl.

⇦

⇨

40 mL of 0.1 M ammonia solution is mixed with 20 mL of 0.1 M HCl. What is the pH of the mixture? ( pKb of ammonia solution is 4.74)

Options

(a) 4.74
(b) 2.26
(c) 9.26
(d) 5

Correct Answer:

9.26

Explanation:

40mL of 0.1 M ammonia solution = 40×0.1
= 4 milli equivalent ammonia solution,
20 mL of 0.1 M HCl = 20×0.1,
= 2 milliequivalent of HCl,
NH₄OH + HCl → NH₄Cl + H₂O. Initial milli.eqv. 4 2 0. Milli-eqv.after 4-2 0 2 reaction = 2. Therefore pOH = pK(b) + log[NH₄Cl]/NH₄OH] = 4.74 + log2/2
= 4.74 + log 1 = 4.74.
Therefore pH = 14 – 4.74 = 9.26.

Related Questions:

1. C₃H₉N cannot represent
2. Order of reaction is decided by
3. Which is a metalloid
4. The number of atoms in 0.1 mol of a triatomic gas is (Na = 6.02 x 10²³ mol⁻¹)
5. The catalyst used in Ziegler process for polythylene manufacture

Topics: Equilibrium (104)
Subject: Chemistry (2512)

---

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

---

Share this page with your friends