Give reasons for the following:
(i) N₂ is less reactive at room temperature.

(ii) H₂Te is the strongest reducing agent amongst all the hydrides of Group 16 elements.

(iii) Helium is used in diving apparatus as a diluent for oxygen.

(a) Write the hybridization and shape of the following complexes:

(i) [CoF₆]^3–

(ii) [Ni (CN)₄]^2–

(Atomic number: Co = 27, Ni = 28)

(b) Out of NH₃ and CO, which ligand forms a more stable complex with a transition metal and why?

Calculate the freezing point of the solution when 31 g of ethylene glycol (C₂H₆O₂) is dissolved in 500 g of water. (K_f for water = 1.86 K kg mol^–1)

Define the following terms:

(i) Primitive unit cells

(ii) Schottky defect

(iii) Ferromagnetism

The rate constant of a first order reaction increases from 2 — 10^-2 to 4 — 10^-2when the temperature changes from 300 K to 310 K. Calculate the energy of activation (E_a).

(log 2 = 0.301, log 3 = 0.4771, log 4 = 0.6021)

Define the following terms:
(i) Brownian movement
(ii) Peptization
(iii) Multimolecular colloids

17.

Calculate E.M.F. and G for the following cell:

The conductivity of 0.20 mol L^-1 solution of KCl is 2.48 x 10^-2 S cm^-1. Calculate its molar conductivity and degree of dissociation  (K⁺) = 73.56 S cm² mol^-1 and  (Cl^-)= 76.5 S

(b) What type of battery is mercury cell? Why is it more advantageous than dry cell?

Which would undergo S_N1 reaction faster in the following pair?