General Science — MCQ Practice Questions & Answers

Question 1

Which of the following compounds exhibits both ionic and covalent bonding characteristics and is commonly used in coordination chemistry?

Accepted Answer

Correct answer: B. Potassium hexacyanoferrate(III) — Potassium hexacyanoferrate(III) contains both ionic bonds (between K⁺ and the [Fe(CN)₆]³⁻ complex) and covalent bonds (between Fe and CN ligands, and within the CN groups). This complex salt is extensively used in coordination chemistry and analytical procedures like the Prussian blue test.

Answer

A. Sodium chloride

Answer

C. Carbon dioxide

Answer

D. Calcium oxide

Question 2

Which of the following substances will have the lowest lattice enthalpy among ionic compounds?

Accepted Answer

Correct answer: C. CsI — Lattice enthalpy depends inversely on ionic radius and directly on ionic charge. CsI has the lowest lattice enthalpy (~604 kJ/mol) because both Cs⁺ and I⁻ are large ions with 1+ and 1- charges respectively. In contrast, MgO has very high lattice enthalpy due to small, highly charged ions (Mg²⁺ and O²⁻), while NaCl and CaF₂ have intermediate values.

Answer

A. NaCl

Answer

B. MgO

Answer

D. CaF₂

General Science - MCQ Practice Questions