Which catalyst is used in the decomposition of H₂O₂ in laboratory preparation of oxygen? MCQ with Answer and Explanation

Explanation:
Ionic character increases with the difference in electronegativity between bonding atoms. In hydrogen halides, electronegativity decreases from F to I (F: 4.0, Cl: 3.0, Br: 2.8, I: 2.5). Thus HF has the largest electronegativity difference (1.9) and highest ionic character. The trend: HF > HCl > HBr > HI. However, HF is still a covalent polar molecule. Exam tip: Electronegativity difference > 1.7 usually indicates ionic bond.

Explanation:
Sulphuric acid (H₂SO₄) is historically called oil of vitriol because it was prepared by distilling green vitriol (ferrous sulfate heptahydrate). It is a dense, oily liquid. Nitric acid is aqua fortis, hydrochloric acid was called muriatic acid or spirit of salt. Sulphuric acid is the king of chemicals due to its widespread use in industries like fertilizer, petroleum refining, and chemical synthesis.

Explanation:
Hydrogen peroxide decomposes into water and oxygen. A single reactant breaks down into two or more products, so it is a decomposition reaction. This particular reaction can be catalyzed by MnO₂ or light. It is also a disproportionation redox reaction where O in H₂O₂ (-1) goes to -2 in H₂O and 0 in O₂.