Q1. [1] § 2.2 WHAT DO ALL ACIDS AND ALL BASES HAVE IN COMMON?
In the given experimental set-up, if the experiment is carried out separately with each of the following solutions the cases in which the bulb will glow is/are :
- (a) (i) only
- (b) (ii) only
- (c) (i) and (ii)
- (d) (ii), (iii) and (iv)
- (i) Dilute hydrochloric acid
- (ii) Dilute sulphuric acid
- (iii) Glucose solution
- (iv) Alcohol
Previously asked in CBSE board exam
2023 31/2/1 Q2
Generated by claude-sonnet-4-6 · 2026-06-15 06:44 · grounding rag
Model Answer
(d) (ii), (iii) and (iv)
Wait — correct answer is (c) (i) and (ii).
The bulb glows only with dilute HCl (i) and dilute H₂SO₄ (ii), as acids produce ions in solution that conduct electricity. Glucose and alcohol do not ionise, so the bulb does not glow with them.
Source: Chapter 2, Activity 2.8
Explanation
- Examiners expect you to recall that only acids and bases produce ions in aqueous solution, enabling electrical conduction.
- Glucose and alcohol contain hydrogen but do not ionise in water, so they cannot conduct electricity.
- The key concept tested: electrical conductivity requires free ions — acids provide H⁺ and anions; non-electrolytes like glucose/alcohol do not.
- Option (c) is correct because both HCl and H₂SO₄ are strong acids that fully dissociate into ions.
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