Q1. Which of the following is commonly present in the acids?
(a) Oxygen
(b) Hydrogen
(c) Sulphur
(d) Nitrogen
(UPSC Prelims 1981)
Answer: (b) Hydrogen
Explanation: All acids contain hydrogen ions (H⁺), which are responsible for their acidic properties. When dissolved in water, acids release hydrogen ions, making hydrogen the defining element in acidic compounds.
Q2. Solution of washing soda in water is
(a) Acidic
(b) Basic
(c) Neutral
(d) Sour
(UPSC Prelims 1984)
Answer: (b) Basic
Explanation: Washing soda is chemically known as sodium carbonate (Na₂CO₃). When dissolved in water, it forms a basic solution due to the release of carbonate ions, which increase the pH level. It is commonly used in cleaning and laundry.