Q1. [4] § 2.4 MORE ABOUT SALTS
Salts play a very important role in our daily life. Sodium chloride which is known as common salt is used almost in every kitchen. Baking soda is also a salt used in faster cooking as well as in baking industry. The family of salts is classified on the basis of cations and anions present in them.
Read the source and answer the sub-parts that follow.
- (a) Identify the acid and base from which Sodium chloride is formed. [1]
- (b) Find the cation and the anion present in Calcium sulphate. [1]
- (c) "Sodium chloride and washing soda both belong to the same family of salts." Justify this statement. [2]
Previously asked in CBSE board exam
2024 31/2/1 Q37
Generated by claude-sonnet-4-6 · 2026-06-15 06:46 · grounding stimulus
Model Answer
(a) Sodium chloride (NaCl) is formed from:
- Acid: Hydrochloric acid (HCl)
- Base: Sodium hydroxide (NaOH)
(b) In Calcium sulphate (CaSO₄):
- Cation: Ca²⁺ (Calcium ion)
- Anion: SO₄²⁻ (Sulphate ion)
(c) Salts are classified into families based on the cations and anions present in them. Sodium chloride (NaCl) contains the Na⁺ cation and Cl⁻ anion. Washing soda (Na₂CO₃) also contains the Na⁺ cation. Since both salts share the same cation (Na⁺), they belong to the sodium family of salts. Hence, the statement is justified.
Source: Chapter 2 – Acids, Bases and Salts
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Explanation
- (a): Always identify the parent acid (provides anion) and parent base (provides cation) of a salt. NaCl → HCl + NaOH.
- (b): Dissociate the formula: CaSO₄ → Ca²⁺ + SO₄²⁻. Cation is the positive ion, anion is the negative ion.
- (c): The key phrase from the passage is "family of salts is classified on the basis of cations and anions." Use this directly to justify: both NaCl and Na₂CO₃ share Na⁺, so same family. 2-mark justification needs both the rule AND its application.
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