NCERT Exemplar Class 11 Chemistry Chapter 11 MCQ

(d) Quick limeExplanation:Ammonia, with H2SO4 forms ammonium sulphate, with CaCl2 forms CaCl2.8NH3 and with P2O5 gives NH4PO3, hence these reagents cannot be used for drying ammonia.

(c) Strong attractive force between the atomsExplanation:Inert gases condense into the solid state at very low temperature as there is strong attractive force between the atoms.In solid state, Van der Waals attractive forces are predominant between the atoms. The attractive force increases with the size of the atom as a result of the increase in polarizability and the decrease in ionization potential.

(b) Lewis AcidsExplanation:The boron atom in trihaldies has only six electrons in the valence shell and hence can accept a pair of electrons in the vacant p-orbital to complete its octet. As a result, boron trihaldies act as a Lewis acids.

(a) Increase to 1.5 timesExplanation:O3 → O2 + [O]1 mole of O3 on heating produces 1 mole of O2 and 1 mole of [O], hence its volume increases to 1.5 times.

(b) B > P > As > BiExplanation:BCl3 is trigonal planar in structure and bond angles are 120° each. PCl3, AsCl3, and BiCl3 are pyramidal in shape with sp³ hybridization.In all of them, the bond angles are less than the normal tetrahedral angle of 109.28, and also these bond angles decrease down the group. Therefore, the correct order of bond angles is as follows:B > P > As > Bi