Relevant Titles
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CBSE Class 11 Chemistry MCQs: Indicators and Common Ion Effect Practice Test
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NCERT Class 11 Chemistry Chapter 7 Equilibrium – Indicators and Common Ion Effect MCQs
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CBSE Class 11 Chemistry Quiz – Indicators and Common Ion Effect (Equilibrium)
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Free CBSE Class 11 Chemistry MCQ Test: Common Ion Effect and Indicators
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Online CBSE Class 11 Chemistry Practice Test on Indicators and Common Ion Effect
Introduction
Understanding Indicators and the Common Ion Effect is crucial for mastering Chapter 7 – Equilibrium in CBSE Class 11 Physical Chemistry. These topics explain how chemical equilibria shift in response to the addition of ions and how acid-base indicators help in detecting neutralization points in titrations.
This online MCQ practice test is designed strictly as per the NCERT Class 11 Chemistry syllabus and the latest CBSE exam pattern. Each question is concept-based and accompanied by detailed explanations to help students understand equilibrium behavior, the Le Chatelier’s Principle, and indicator pH ranges.
Perfect for CBSE board exam preparation, this quiz also benefits students preparing for competitive exams like NEET and JEE, where equilibrium concepts form the foundation for problem-solving. Take this interactive 30-minute practice quiz to test your grasp of the Common Ion Effect, buffer action, and acid-base indicators — and strengthen your Chemistry fundamentals effectively.
Sample MCQs (with Answers and Explanations)
Q1. Which indicator is most suitable for titration between a strong acid and a strong base?
A) Methyl orange B) Phenolphthalein C) Bromothymol blue D) Litmus
Answer: C) Bromothymol blue
Explanation: Bromothymol blue changes color near pH 7, making it suitable for strong acid–strong base titrations where the equivalence point is neutral.
Q2. The Common Ion Effect causes:
A) Increased ionization of weak acid B) Decreased ionization of weak acid C) Neutral pH D) Increased solubility
Answer: B) Decreased ionization of weak acid
Explanation: The addition of a common ion shifts equilibrium toward the undissociated form, reducing ionization — a direct application of Le Chatelier’s Principle.
Q3. Methyl orange changes color between pH values:
A) 3.1–4.4 B) 6.0–7.6 C) 8.2–10.0 D) 2.0–3.0
Answer: A) 3.1–4.4
Explanation: Methyl orange changes from red (acidic) to yellow (basic) within the pH range 3.1–4.4, making it ideal for strong acid–weak base titrations.
Q4. Adding sodium acetate to acetic acid solution will:
A) Increase ionization B) Decrease ionization C) Not affect ionization D) Neutralize the solution
Answer: B) Decrease ionization
Explanation: Sodium acetate provides acetate ions (common ion), which suppress the ionization of acetic acid, demonstrating the common-ion effect.
Q5. The end point of an acid-base titration depends on:
A) The pH range of the indicator B) Temperature only C) Concentration only D) None of these
Answer: A) The pH range of the indicator
Explanation: The visible end point of a titration occurs when the solution pH equals the indicator’s transition range, causing a color change.