Short Answer TypeGive 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. (Kf for water = 1.86 K kg mol–1)
Define the following terms:
(i) Primitive unit cells
(ii) Schottky defect
(iii) Ferromagnetism
(i) Primitive unit cells are defined as the unit cells in which the constituent particles are present only at the corner positions.
(ii) Schottky defect: Schottky defect is basically a vacancy defect shown ionic solids. In this defect, an equal no cation and anion are missing to maintain electrical neutrality. It decreases the density of a substance. An Ionic substance containing the similar size of cations and anion show this type of defect. For example: NaCl, KCl, CsCl, AgBr, etc.
(iii) Ferromagnetism is defined as the phenomenon in which substances, such as iron, cobalt and nickel, are strongly attracted by a magnetic field. Such substances are called ferromagnetic substances.
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 (Ea).
(log 2 = 0.301, log 3 = 0.4771, log 4 = 0.6021)
Define the following terms:
(i) Brownian movement
(ii) Peptization
(iii) Multimolecular colloids
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?
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