Course Code: BCHCT-137
Assignment Code: BCHCT-137/TMA/2023
Maximum Marks: 100

PART A: COORDINATION CHEMISTRY

1 a) In potassium which of the two orbitals \(3 d\) and \(4 s\) has higher energy? Give reasons.

b) Why are high oxidation states stable when we move from the second to the third row of the transition series?
\(2 \quad\) In \(\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\) the observed magnetic moment is higher than the spin-only value explain the reason.

3 Why do the colours arise in lanthanoid ions and why are the colours pale?

4 What is the definition of a complex? Determine the coordination number and the oxidation state of the transition metal ion in the \(\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}\) complex.

5 What will be the names of the following ligands when they are present in a complex entity:
\(\mathrm{CN}^*, \mathrm{O}^{2-}, \mathrm{Me}_2 \mathrm{As}^{-},\left(\mathrm{CH}_3 \mathrm{COCHCOCH}_3\right)_2\) and \(\mathrm{H}_2 \mathrm{O}\).

6 What are the different types of structural isomerism? Give example of any one of them.

7 Explain the structure of \(\left[\mathrm{MnCl}_4\right]^{2-}\) with the help of valence bond theory.

8 Predict the geometry of the \(\mathrm{Ni}(\mathrm{CO})_4\) complex showing their hybridized orbitals.

9 Calculate the crystal field stabilization energy (CFSE) of an octahedral complex with four electrons in the \(d\) orbitals.

10 What is the definition of a complex? Determine the coordination number and the oxidation state of the transition metal ion in the \(\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}\) complex.
What will be the names of the following ligands when they are present in a complex entity:
\[
\mathrm{CN}^*, \mathrm{O}^{2-}, \mathrm{Me}_2 \mathrm{As}^*,\left(\mathrm{CH}_3 \mathrm{COCHCOCH}_3\right)_2 \text { and } \mathrm{H}_2 \mathrm{O} \text {. }
\]
What are the different types of structural isomerism? Give example of any one of them.
Calculate the spin-only magnetic moment for low-spin octahedral complex of \(d^5\) and \(d^6\) ions.

PART B: STATES OF MATTER \& CHEMICAL KINETICS

11 State postulates of kinetic theory of gases and derive the equation: \(p V=\frac{1}{3} m N \bar{u}^2\).

12 Define mean free path of a molecule. Calculate the mean free path of oxygen molecule at 300 \(\mathrm{K}\) and \(1.013 \times 10^5 \mathrm{~Pa}\). The collision diameter for the molecule is \(1.20 \times 10^{-10} \mathrm{~m}\).

13 What are critical constants? Derive the relationships between the critical constants and van der Waals constants.

14 a) List different factors affecting the rates of chemical reactions.

b) Derive the integrated rate equation for a second order reaction in which a single reactant forms the product and the reaction rate depends on the second power of the reactant concentration.

15 a) What are clock reactions? What type of rate of reaction is determined by these reactions?

b) Derive an expression relating the activation energy with the rate constants at two different temperatures.

16 The first-order decomposition of \(\mathrm{N}_2 \mathrm{O}_5\) is studied at \(340 \mathrm{~K}\) starting with \(2.50 \mathrm{~g}\) of \(\mathrm{N}_2 \mathrm{O}_5\). If its amount decreases to \(1.50 \mathrm{~g}\) in \(100 \mathrm{~s}\), then calculate:

a) the rate constant
b) the half life of reaction
c) the time required for the amount of \(\mathrm{N}_2 \mathrm{O}_5\) to reduce to \(0.5 \mathrm{~g}\).

17 What are the various intermolecular forces that are responsible for the conversion of gases into liquids and solids?

18 Explain with suitable diagrams the planes of symmetry and the axes of symmetry in the cubic system.

19 Explain the parameters of a unit cell with the help of a suitable diagram.

20 Tungsten form \(b c c\) crystals. Its cell-edge length is \(2.18 \times 10^{-10}\). Find the density of tungsten. (Given: Molar mass of tungsten \(=183.84 \mathrm{~g}\) per mol).