General Science — MCQ Practice Questions & Answers

Question 1

In the reaction between potassium permanganate and oxalic acid in acidic medium, what is the ratio of KMnO₄ to H₂C₂O₄ in the balanced equation?

Accepted Answer

Correct answer: B. 2:5 — The balanced equation for this redox reaction in acidic medium is: 2KMnO₄ + 5H₂C₂O₄ + 3H₂SO₄ → K₂SO₄ + 2MnSO₄ + 10CO₂ + 8H₂O. Potassium permanganate acts as an oxidizing agent (Mn⁷⁺ → Mn²⁺), while oxalic acid is oxidized (C²⁺ → C⁴⁺), giving the 2:5 molar ratio.

Answer

A. 1:2

Answer

C. 3:5

Answer

D. 5:2

Question 2

What is the hybridization state of the central carbon atom in the carbonate ion (CO₃²⁻)?

Accepted Answer

Correct answer: B. sp² — In the carbonate ion CO₃²⁻, the central carbon atom forms three sigma bonds with oxygen atoms and is involved in resonance structures with delocalized pi electrons. This trigonal planar geometry requires sp² hybridization, with three hybrid orbitals arranged at 120° angles and one unhybridized p orbital for pi bonding.

Answer

A. sp

Answer

C. sp³

Answer

D. sp³d

General Science - MCQ Practice Questions