Chapter-7 p-Block Elements MCQs
Q 81.: Which of the following gas mixture is used by the scuba divers inside the sea ?
(A) O2 + N2
(B) O2 + He
(C) O2 + Ne
(D) O2 + Ar
Option – B
Q 82.: Least stable oxide of chlorine is
(A) Cl2O
(B) ClO2
(C) Cl2O7
(D) ClO3
Option – A
Q 83.: One gas bleaches the colour of flower by reduction and another gas by oxidation. The gases respectively, are
(A) SO2 and Cl2
(B) CO and Cl2
(C) NH3 and SO2
(D) H2S and Br2
Option – A
Q 84.: When chlorine gas reacts with dilute NaOH under cold conditions, the oxidation state of chlorine changes from zero to
(A) -1 and +5
(B) +1 and +4
(C) +5 and +3
(D) -1 and +1
Option – D
Q 85.: The number of pπ-dπ ‘pi’ bonds present in XeO3 and XeO4 molecules, respectively
(A) 4, 2
(B) 2, 3
(C) 4, 3
(D) 3, 4
Option – D
Q 86.: Which of the following halogens does not exhibit a positive oxidation number in their compounds ?
(A) Iodine
(B) Fluorine
(C) Bromine
(D) Chlorine
Option – B
Q 87.: Solubility of iodine in water may be increased by adding
(A) Chloroform
(B) Carbon disulphide
(C) Potassium iodide
(D) Sodium thiosulphate
Option – C
Q 88.: Which one of the following oxides is expected to exhibit paramagnetic behaviour ?
(A) CO2
(B) SiO2
(C) ClO2
(D) SO2
Option – C
Q 89.: Which of the following is not obtained by direct reaction of constituent elements ?
(A) XeO3
(B) XeF2
(C) XeF4
(D) XeF6
Option – A
Q 90.: Which of the following is square planar ?
(A) XeF2
(B) XeF4
(C) XeF6
(D) XeOF2
Option – B