MCQs On P-Block Elements

 P-Block Elements

Prepared By: Saif-ur-Rehman Chachar

Question 1
When Cl2 gas reacts with hot and concentrated sodium hydroxide solution, the oxidation number of chlorine changes from
A.Zero to – 1 and zero to +3
B.Zero to + 1 and zero to –3
C.Zero to + 1 and zero to –5
D.Zero to – 1 and zero to +5

Question 2
In which of the following compounds, nitrogen exhibits highest oxidation state?
A.N3H
B.NH2OH
C.N2H4
D.NH3

Question 3
Three reactions involving H2PO4- are given below
(i) H3PO4 + H2O ® H3O+ + H2PO4-
(ii) H2PO4- + H2O ® HPO42- + H3O+
(iii) H2PO4- + OH- ® H3PO4 + O2-

In which of the above does H2PO4- act as an acid?
A.(i) only
B.(ii) only
C.(iii) only
D.(i) and (ii)

Question 4
The correct order of increasing bond angles in the following species is [CBSE AIPMT 2010]
A.Cl2O < ClO2 < ClO2-
B.ClO2- < Cl2O < ClO2
C.Cl2O < ClO2- < ClO2
D.ClO2 < Cl2O < ClO2-

Question 5
The tendency of BF3, BCl3 and BBr3 to behave as Lewis acid decreases in the sequence:
A.BCl3 > BF3 > BBr3
B.BF3 > BCl3 > BBr3
C.BBr3 > BF3 > BCl3
D.BBR3 > BCl3 > BF3

Question 6
P4O10 is the anhydride of
A.H3PO2
B.H3PO3
C.H3PO4
D.H4P2O7

Question 7
Which of the following statements regarding ozone is not correct?
A.The oxygen-oxygen bond length in ozone is identical with that of molecular oxygen
B.The ozone is response hybrid of two structures
C.The ozone molecule is angular in shape
D.Ozone is used as a germicide and disinfectant for the purification of air.

Question 8
Which of the following contains P - O - P bond?
A.Hypophosphorous acid
B.Phosphorous acid
C.Pyrophosphoric acid
D.Orthophosphoric acid

Question 9
Which noble gas is most abundant in atmosphere?
A.He
B.Ne
C.Ar
D.Kr

Question 10
The reaction of P4 with X leads selectively to P4O6. The X is
A.Dry O2
B.A mixture of O2 and N2
C.Moist O2
D.O2 in the presence of aqueous NaOH

Question 11
Which of the following reactions of xenon compounds is not feasible?
A.XeO3 + 6HF ® XeF6 + 3H2O
B.3XeF4 + 6H2O ® 2Xe + XeO3 + 12HF + 1.5O2
C.2XeF2 + 2H2O ® 2Xe + 4HF + O2
D.XeF6 + RbF ® Rb [XeF7]

Question 12
In which of the following arrangements, the sequence is not strictly according to the property written against it?
A.CO2 < SiO2 < SnO2 < PbO2 : Increasing oxidizing power
B.HF < HCl < HBr < HI : Increasing acid strength
C.NH3 < PH3 < AsH3 < SbH3 : Increasing basic strength
D.B < C < O < N : Increasing first ionization enthalpy

Question 13
Among the following which is the strongest oxidizing agent?
A.Br2
B.I2
C.Cl2
D.F2

Question 14
The brown ring test for nitrates depends on
A.reduction of ferrous sulphate to iron
B.oxidation of nitric oxide to nitrogen dioxide
C.the reduction of nitrate to nitric oxide
D.oxidising action of sulphuric acid

Question 15
One mole of magnesium nitride on the reaction with an excess of water gives:
A.one mole of ammonia
B.one mole of nitric acid
C.two moles of ammonia
D.two moles of nitric acid