Write down the outermost electronic configurations of alkali metals. How will you justify their placement in group 1 of the periodic table?

5

(a)

Write the significance/applications of dipole moment.

5

(a)

What is an ionic bond? With two suitable examples the difference between an ionic and a covalent bond?

5

(a)

At 60°C, dinitrogen tetroxide is 50 per cent dissociated. Calculate the standard free energy change at this temperature and at one atmosphere.

5

(a)

Enthalpy is an extensive property. In general, if enthalpy of an overall reaction A\(\rightarrow \) B along one route is \(\Delta _{ r }H \ and \ \Delta _{ r }H_{ 1 },\Delta _{ r }H_{ 2 },\Delta _{ r }H_{ 3 }....\)represent enthalpies of intermediate reactions leading to product B. What will be the relation between \(\Delta _{ r }H\) overall reaction and \(\Delta _{ r }H_{ 1 },\Delta _{ r }H_{ 2 }\) .....etc., for intermediate reactions.

5

(a)

A sparingly soluble salt gets precipitated only when the product of concentration of its ions in the solution (Q_sp ) becomes greater than its solubility product. If the solubility of BaSO₄ in water is 8 x 10^-4 mol dm^-3 . Calculate its solubility in 0.01 mol dm^-3 of H₂SO₄ .

5

(a)

What mass of hydrogen peroxide will be present in 2L of a 5M solution?

5

(a)

What are the allotropes? Sketch the structure of two allotropes of carbon namely diamond and graphite.What is the impact of structure on physical properties of two allotropes?

5

(a)

Pay load is defined as the difference between the mass of the displaced air and the mass of the balloon. Calculate the pay load when a balloon of radius 10 m, mass 100 kg is filled with helium at 1.66 bar at 27^oC (Density of air = 1.2 kg m-3 and R = 0.083 bar dm³ K-1 mol^-1).

5

(a)