The p-Block Elements Class 12 Chemistry MCQs Pdf
1. H2S is more acidic than H2O because
(a) oxygen is more electronegative than sulphur.
(b) atomic number of sulphur is higher than oxygen.
(c) H — S bond dissociation energy is less as compared to H — O bond.
(d) H — O bond dissociation energy is less also compared to H — S bond.
Answer
Answer: b
2. The boiling points of hydrides of group 16 are in the order
(a) H2O > H2Te > H2S > H2Se
(b) H2O > H2S > H2Se > H2Te
(c) H2O > H2Te > H2Se > H2S
(d) None of these
Answer
Answer: b
3. In the manufacture of sulphuric acid by contact process Tyndall box is used to
(a) convert SO2 and SO3
(b) test the presence of dust particles
(c) filter dust particles
(d) remove impurities
Answer
Answer: b
4. Fluorine differs from rest of the halogens in some of its properties. This is due to
(a) its smaller size and high electronegativity.
(b) lack of d-orbitals.
(c) low bond dissociation energy.
(d) All of the these.
Answer
Answer: b
5. The set with correct order of acidity is
(a) HClO < HClO2 < HClO3 < HClO4
(b) HClO4 < HClO3 < HClO2 < HClO
(c) HClO < HClO4 < HClO3 < HClO2
(d) HClO4 < HClO2 < HClO3 < HClO
Answer
Answer: b
6. When chlorine reacts with cold and dilute solution of sodium hydroxide, it forms
(a) Cl– and ClO–
(b) Cl– and ClO2–
(c) Cl– and ClO3–
(d) Cl– and ClO4–
Answer
Answer: a
7. The formation of O2+ [PtF6]– is the basis for the formation of first xenon compound. This is because
(a) O2 and Xe have different sizes.
(b) both O2 and Xe are gases.
(c) O2 and Xe have comparable electro-negativities.
(d) O2 and Xe have comparable ionisation enthalpies.
Answer
Answer: d
8. Partial hydrolysis of XeF4 gives
(a) XeO3
(b) XeOF2
(c) XeOF4
(d) XeF2
Answer
Answer: b
9. Helium is preferred to be used in balloons instead of hydrogen because it is
(a) incombustible
(b) lighter than hydrogen
(c) more abundant than hydrogen
(d) non polarizable
Answer
Answer: a
10. The increasing order of reducing power of the halogen acids is
(a) HF < HCl < HBr < HI
(b) HI < HBr < HCl < HF
(c) HBr < HCl < HF < HI
(d) HCl < HBr < HF < HI
Answer
Answer: a
