Salts in Daily Life
Salts are chemical compounds resulting from the neutralization of an acid and a base. They are crucial in food, industry, and health. Let's address each point sequentially.
(a) Identify the acid and base from which Sodium chloride is formed.
Sodium chloride (NaCl) is produced through the neutralization reaction between:
- Hydrochloric acid (HCl) as the acid.
- Sodium hydroxide (NaOH) as the base.
Reaction: HCl + NaOH → NaCl + H₂O
(b) Find the cation and the anion present in Calcium sulphate.
- The chemical formula for Calcium sulphate is CaSO₄.
- Cation: Ca²⁺ (Calcium ion).
- Anion: SO₄²⁻ (Sulphate ion).
(c) “Sodium chloride and washing soda both belong to the same family of salts.” Justify this statement.
- Both Sodium chloride (NaCl) and washing soda (Na₂CO₃) share the same cation, sodium (Na⁺).
- Salts with a common cation or anion are classified within the same family.
- Consequently, both salts are categorized under the sodium salt family.
OR
(c) Define the term pH scale. Name the salt obtained by the reaction of Potassium hydroxide and Sulphuric acid and give the pH value of its aqueous solution.
- pH scale: This scale quantifies the hydrogen ion concentration (H⁺) in a solution, ranging from 0 to 14.
- pH < 7 indicates an acidic solution.
- pH = 7 signifies a neutral solution.
- pH > 7 denotes a basic solution.
- The reaction between Potassium hydroxide (KOH) and Sulphuric acid (H₂SO₄) yields:
2KOH + H₂SO₄ → K₂SO₄ + 2H₂O
The resulting salt is Potassium sulphate (K₂SO₄).
- Potassium sulphate is a neutral salt (formed from a strong acid and a strong base), so its pH is approximately 7.
Final Answers:
(a) Acid: HCl, Base: NaOH
(b) Cation: Ca²⁺, Anion: SO₄²⁻
(c) Both NaCl and Na₂CO₃ contain the Na⁺ ion, placing them in the same family.
OR
(c) The pH scale measures hydrogen ion concentration; the salt formed is Potassium sulphate (K₂SO₄); its pH is approximately 7.