Draw the structure of XeF4 and OSF4 according to VSEPR theory clearly indicating the state of hybridisation of the central atom and lone pair of electrons (if any) on the central atom.

A compound AB has rock salt type structure. The formula weight of AB is 6.023 Y amu, and the closest A - B distance is Y^1/3 nm, where Y is an arbitrary number
(a) Find the density of the lattice
(b) If the density of lattice is found to be 20 kg m^-3, then predict the type of defect

1.22 g of benzoic acid is dissolved in 100 g of acetone and 100 g of benzene separately. Boiling point of the solution in acetone increases by 0.17 ^oC, while that in the benzene increases by 0.13^oC; K_b for acetone and benzene is 1.7 K kg mol^-1 and 2.6 K kg mol^-1. Find molecular weight of the benzoic acid in two cases and justify your answer.

Find the equilibrium constant for the reaction,
In²⁺ + Cu²⁺ $$\to$$ In³⁺ + Cu⁺ at 298 K
given
$$E_{C{u^{2 + }}/C{u^ + }}^o$$ = 0.15 V; $$E_{l{n^{2 + }}/l{n^ + }}^o$$ = -0.40 V; $$E_{l{n^{3 + }}/l{n^ + }}^o$$ = -0.42 V;