Class 11 • Chemistry • Chapter 6
Equilibrium
True & False Quiz
Balance. Shift. Coexist.
✓True
✗False
25
Questions
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Ch.6
Chapter
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XI
Class
Why True & False for Equilibrium?
How this format sharpens your conceptual clarity
🔵 Equilibrium describes the dynamic balance between forward and reverse reactions — central to industrial processes like the Haber and Contact processes.
✅ T/F questions target Le Chatelier's principle, equilibrium constant expressions (Kc, Kp), ionic equilibria, and acid-base theories.
🎯 Classic trap: at equilibrium the rates of forward and reverse reactions are EQUAL, not zero — the reaction never actually stops.
📋
Read each statement carefully. Click True or False — instant feedback with explanation appears. Submit anytime; unattempted questions are marked Skipped.
Q 1
Equilibrium in a reversible reaction is established when the forward and reverse reactions occur at equal rates.
Q 2
Chemical equilibrium can be established only in a closed system.
Q 3
In a state of dynamic equilibrium, all chemical reactions stop completely.
Q 4
In a homogeneous equilibrium, all reactants and products are present in the same physical state.
Q 5
The equilibrium constant changes when the initial concentration of reactants is changed.
Q 6
For the reaction \(\mathrm{N_2(g)+3H_2(g)\rightleftharpoons2NH_3(g)}\), increasing pressure favours ammonia formation.
Q 7
Adding a catalyst changes the value of the equilibrium constant.
Q 8
For an exothermic reaction, increasing temperature generally decreases the equilibrium constant.
Q 9
If \(Q_c<K_c\), the reaction proceeds in the forward direction until equilibrium is reached.
Q 10
The equilibrium constant for a reverse reaction is the reciprocal of the equilibrium constant for the forward reaction.
Q 11
According to Arrhenius theory, acids produce \(OH^-\) ions in water.
Q 12
According to the Brønsted-Lowry concept, a base is a proton acceptor.
Q 13
Every Lewis acid contains hydrogen.
Q 14
Water can behave as both an acid and a base.
Q 15
At \(25^\circ\mathrm{C}\), the ionic product of water is \(K_w=1.0\times10^{-14}\).
Q 16
A solution having \(pH=3\) is more acidic than a solution having \(pH=6\).
Q 17
A buffer solution completely prevents any change in pH when acid or base is added.
Q 18
An acidic buffer can be prepared using acetic acid and sodium acetate.
Q 19
The common ion effect suppresses the ionization of a weak electrolyte.
Q 20
The solubility product constant, \(K_{sp}\), depends only on temperature.
Q 21
If \(Q_{sp}>K_{sp}\), precipitation of the sparingly soluble salt occurs.
Q 22
The concentration of a pure solid is included in the expression for \(K_{sp}\).
Q 23
A salt formed from a strong acid and a strong base generally produces a neutral aqueous solution.
Q 24
For the reaction \(\mathrm{H_2(g)+I_2(g)\rightleftharpoons2HI(g)}\), \(K_p=K_c\).
Q 25
Equilibrium concepts are useful for understanding industrial processes such as the Haber process and for predicting the direction and extent of chemical reactions.
Key Takeaways — Equilibrium
Core facts for CBSE Boards & exams
1
Chemical equilibrium is dynamic: forward rate = reverse rate, concentrations remain constant (not equal).
2
Le Chatelier's Principle: a system at equilibrium shifts to counteract any imposed change (concentration, pressure, temperature).
3
Kp = Kc(RT)∆n, where ∆n = moles of gaseous products − moles of gaseous reactants.
4
Arrhenius: acid gives H⁺ in water, base gives OH⁻. Brønsted-Lowry: acid = proton donor, base = proton acceptor. Lewis: acid = electron-pair acceptor, base = electron-pair donor.
5
pH = −log[H⁺]; pOH = −log[OH⁻]; pH + pOH = 14 at 25°C.
6
Common ion effect suppresses ionisation of a weak electrolyte; buffer solutions resist pH change on adding small amounts of acid/base.
7
Solubility product Ksp applies to sparingly soluble salts; precipitation occurs when ionic product exceeds Ksp.