NCERT  ·  Chemistry  ·  Class XI  ·  Ch.6

Equilibrium
MCQ Master Series

Dynamic Equilibrium · Law of Mass Action · Kc & Kp · Le Chatelier · Ionic Equilibrium

🎯 50 Questions
⏱ 35 min Suggested
📊 3 Difficulty Tiers
🗂 6 Topics
⚡ Start Quiz 📊 Analytics
Explore
Question Intelligence

Quiz Analytics

A data-driven breakdown of all 50 questions by difficulty, exam origin and topic distribution.

📈 Distribution Overview

50
Total Questions
CBSE Board
25
JEE Level
16
NEET Level
9

🗂 Topic Coverage

Physical Equilibrium
14%
Law of Mass Action & Kc/Kp
22%
Le Chatelier's Principle
16%
Acids, Bases & Ionic Equil.
20%
pH & Buffer Solutions
16%
Solubility Product
12%
25
CBSE Board
16
JEE Level
9
NEET Level
Conceptual Framework

Key Concept Highlights

6 foundational pillars that power every question in this quiz. Understand these, and the answers follow naturally.

⚖️
Dynamic Equilibrium
At equilibrium, forward and reverse reaction rates are equal — concentrations stay constant but the reaction never stops (dynamic, not static).
📏
Law of Mass Action
Rate of a reaction is proportional to the product of active masses of reactants. Leads to the equilibrium constant expression Kc.
🔄
Kp and Kc Relation
For gaseous equilibria, Kp = Kc(RT)^Δn where Δn is the change in moles of gas. Kp = Kc only when Δn = 0.
🎯
Le Chatelier's Principle
If a system at equilibrium is disturbed (concentration, pressure, temperature), it shifts to partially counteract the change and restore equilibrium.
🧪
Acid-Base Theories
Arrhenius (H⁺/OH⁻ producers), Bronsted-Lowry (proton donor/acceptor), Lewis (electron pair acceptor/donor) — each broadens the definition of acids and bases.
🧂
Buffer & Solubility
Buffer solutions resist pH change on adding small amounts of acid/base. Ksp governs precipitation; common ion effect suppresses solubility of a sparingly soluble salt.
Pedagogical Value

Why MCQs Matter

Multiple-choice questions are not mere guessing games — they are the sharpest diagnostic tool available to a competitive exam aspirant.

~11%

of CBSE Class XI Chemistry — foundation for equilibrium in Class XII

Quick Reference

Important Formula Capsules

6 must-memorise equations that surface repeatedly across CBSE and JEE papers.

Equilibrium Constant
\[ K_c = \dfrac{[C]^c[D]^d}{[A]^a[B]^b} \]
Kp–Kc Relation
\[ K_p = K_c(RT)^{\Delta n_g} \]
Ionic Product of Water
\[ K_w = [H^+][OH^-] = 10^{-14} \; \text{at } 298\,K \]
pH Definition
\[ \text{pH} = -\log_{10}[H^+] \]
Henderson-Hasselbalch
\[ \text{pH} = \text{p}K_a + \log\dfrac{[\text{Salt}]}{[\text{Acid}]} \]
Solubility Product
\[ K_{sp} = [A^{n+}]^p[B^{m-}]^q \]
Learning Outcomes

What You Will Learn

By completing this quiz set you will have exercised all the following competencies.

01 Distinguish physical equilibria from chemical equilibria with real examples
02 Write the equilibrium constant expression Kc for a given reversible reaction
03 Apply the Kp–Kc relation using Δn for gaseous equilibria
04 Predict the direction of shift in equilibrium using Le Chatelier's principle
05 Classify acids and bases using Arrhenius, Bronsted-Lowry, and Lewis concepts
06 Calculate pH of strong and weak acid/base solutions and buffer mixtures
Exam Preparation

Strategy & Preparation Tips

5 evidence-based strategies to maximise your score in CBSE Boards and JEE.

Step 01
Kc Expression Speed Drill
Write Kc for 10 different reversible reactions in under 5 minutes each. Board and JEE MCQs frequently test writing the correct expression with proper exponents.
Step 02
Δn Sign Matters
Δn = moles of gaseous products − moles of gaseous reactants. A negative Δn means Kp < Kc; get the sign right before calculating.
Step 03
Le Chatelier in Four Cases
Memorise system response to: (1) concentration change, (2) pressure/volume change, (3) temperature change, (4) catalyst addition (no shift, only faster equilibrium). This covers nearly all MCQs on this topic.
Step 04
ICE Table for Every Numerical
Set up Initial-Change-Equilibrium tables for every equilibrium numerical. This habit alone eliminates most calculation errors in Kc/Kp problems.
Step 05
pH Numericals Under Pressure
Practise pH of weak acids using Ka and degree of dissociation (α) formulas — a very common JEE and NEET question type.

Ready to Test Your Mastery?

50 questions  ·  Elapsed timer  ·  Instant scored results

⚡ Begin Equilibrium Quiz
🎯 Knowledge Check

Chemistry — Equilibrium

50 Questions Class 11 MCQs
1
Equilibrium in a reversible reaction is attained when:
2
Which of the following represents a dynamic equilibrium?
3
Which of the following is NOT a characteristic of chemical equilibrium?
4
For the reaction \(\mathrm{N_2(g)+3H_2(g)\rightleftharpoons2NH_3(g)}\), the equilibrium constant \(K_c\) is given by
5
Which one of the following represents heterogeneous equilibrium?
6
Which statement regarding equilibrium constant is correct?
7
If the value of \(K_c\) for a reaction is very large, then
8
If the value of the reaction quotient \(Q_c\) is less than \(K_c\), then
9
Which law explains the effect of concentration, pressure and temperature on equilibrium?
10
Which of the following statements is correct regarding a catalyst?
11
According to Le Chatelier's Principle, increasing the concentration of a reactant will
12
For the reaction \(\mathrm{N_2(g)+3H_2(g)\rightleftharpoons2NH_3(g)}\), an increase in pressure shifts the equilibrium
13
Which change does NOT affect the value of the equilibrium constant?
14
For an exothermic reaction, increasing the temperature causes the equilibrium to shift
15
For an endothermic reaction, increasing temperature
16
Which one of the following changes has no effect on a gaseous equilibrium when the number of gaseous moles is equal on both sides?
17
For the reaction \(\mathrm{H_2(g)+I_2(g)\rightleftharpoons2HI(g)}\), the value of \(\Delta n\) is
18
If \(\Delta n=0\), then
19
The equilibrium constant for the reverse reaction is
20
If every coefficient in a balanced chemical equation is multiplied by 2, the new equilibrium constant becomes
21
Ionic equilibrium is established in
22
According to Arrhenius theory, an acid is a substance that
23
According to Arrhenius theory, a base is a substance that
24
According to Brønsted-Lowry theory, a base is
25
In the reaction \(\mathrm{NH_3+H_2O\rightleftharpoons NH_4^++OH^-}\), the conjugate acid of \(NH_3\) is
26
Which of the following is a Lewis acid?
27
Which of the following is a Lewis base?
28
Water behaves as an amphoteric substance because it
29
The ionic product of water at \(25^\circ C\) is
30
Which one of the following solutions is neutral at \(25^\circ C\)?
31
The pH of a solution having hydrogen ion concentration \(1\times10^{-3}\,M\) is
32
The pOH of a solution having hydroxide ion concentration \(1\times10^{-4}\,M\) is
33
At \(25^\circ C\), if the pH of a solution is 5, its pOH is
34
The ionization constant \(K_a\) of a weak acid is a measure of
35
Which of the following acids has the greatest strength?
36
The common ion effect refers to
37
Addition of sodium acetate to acetic acid causes
38
A solution containing acetic acid and sodium acetate is an example of
39
Which of the following is a basic buffer?
40
The primary function of a buffer solution is to
41
A solution of ammonium chloride in water is
42
Sodium acetate solution is
43
A solution of sodium chloride has a pH approximately equal to
44
The solubility product (\(K_{sp}\)) of a sparingly soluble salt depends upon
45
For the equilibrium \(\mathrm{AgCl(s)\rightleftharpoons Ag^+(aq)+Cl^-(aq)}\), the solubility product is
46
If the ionic product (\(Q_{sp}\)) is greater than \(K_{sp}\), then
47
If the ionic product (\(Q_{sp}\)) is less than \(K_{sp}\), then
48
The solubility of silver chloride decreases on adding sodium chloride because of
49
For the reaction \(\mathrm{CaF_2(s)\rightleftharpoons Ca^{2+}(aq)+2F^-(aq)}\), the correct expression for the solubility product is
50
Which one of the following statements is correct regarding equilibrium?
📚
ACADEMIA AETERNUM तमसो मा ज्योतिर्गमय · Est. 2025
Sharing this chapter
Equilibrium | Chemistry Class 11 | Academia Aeternum
Equilibrium | Chemistry Class 11 | Academia Aeternum — Complete Notes & Solutions · academia-aeternum.com
est your understanding of NCERT Class 11 Chemistry Chapter 6 Equilibrium with these carefully designed 50 multiple-choice questions arranged from basic to advanced level. The questions comprehensively cover physical and chemical equilibrium, equilibrium constants, Le Chatelier's Principle, ionic equilibrium, acids and bases, pH, buffer solutions, salt hydrolysis, solubility product, and the common ion effect. Each MCQ includes four options, the correct answer, and a detailed explanation to…
🎓 Class 11 📐 Chemistry 📖 NCERT ✅ Free Access 🏆 CBSE · JEE
Share on
WhatsApp
Telegram
X / Twitter
Facebook
Instagram
Threads
Pinterest
LinkedIn
Quora
Discord
Reddit
Email
academia-aeternum.com/class-11/chemistry/equilibrium/mcqs/ Copy link
💡
Exam tip: Sharing chapter notes with your study group creates a reinforcement loop. Teaching a concept is the fastest path to mastering it.

Frequently Asked Questions

It is an equilibrium where all reactants and products are present in the same phase.

It is an equilibrium involving substances present in more than one phase.

Because their concentration remains constant throughout the reaction.

A large equilibrium constant indicates that products are favoured at equilibrium.

A small equilibrium constant indicates that reactants are favoured.

Reaction quotient is calculated like the equilibrium constant but using concentrations at any instant.

The system is already at equilibrium.

The reaction proceeds in the forward direction.

The reaction proceeds in the reverse direction.

When a system at equilibrium is disturbed, it shifts in the direction that minimizes the disturbance.

Recent Posts

    --:-- ⏱ Time
    ⚡ Progress 0 / 50 answered

    Equilibrium — Learning Resources

    📄 Detailed Notes
    ✔️ True / False
    📚
    ACADEMIA AETERNUM तमसो मा ज्योतिर्गमय · Est. 2025
    Sharing this chapter
    Equilibrium | Chemistry Class 11 | Academia Aeternum
    Equilibrium | Chemistry Class 11 | Academia Aeternum — Complete Notes & Solutions · academia-aeternum.com
    est your understanding of NCERT Class 11 Chemistry Chapter 6 Equilibrium with these carefully designed 50 multiple-choice questions arranged from basic to advanced level. The questions comprehensively cover physical and chemical equilibrium, equilibrium constants, Le Chatelier's Principle, ionic equilibrium, acids and bases, pH, buffer solutions, salt hydrolysis, solubility product, and the common ion effect. Each MCQ includes four options, the correct answer, and a detailed explanation to…
    🎓 Class 11 📐 Chemistry 📖 NCERT ✅ Free Access 🏆 CBSE · JEE
    Share on
    WhatsApp
    Telegram
    X / Twitter
    Facebook
    Instagram
    Threads
    Pinterest
    LinkedIn
    Quora
    Discord
    Reddit
    Email
    academia-aeternum.com/class-11/chemistry/equilibrium/mcqs/ Copy link
    💡
    Exam tip: Sharing chapter notes with your study group creates a reinforcement loop. Teaching a concept is the fastest path to mastering it.

    Get in Touch

    Let's Connect

    Questions, feedback, or suggestions?
    We'd love to hear from you.