When 400 mL of 0.2 M H₂SO₄ solution is mixed with 600 mL of 0.1 M NaOH solution, the increase in temperature of the final solution is __________ $$\times$$ 10^$$-$$2 K. (Round off to the nearest integer).

[Use : H⁺ (aq) + OH^$$-$$ (aq) $$\to$$ H₂O : $$\Delta$$_$$\gamma$$H = $$-$$57.1 kJ mol^$$-$$1]

Specific heat of H₂O = 4.18 J K^$$-$$1 g^$$-$$1

density of H₂O = 1.0 g cm^$$-$$3

Assume no change in volume of solution on mixing.

2SO₂(g) + O₂(g) $$\to$$ 2SO₃(g)

The above reaction is carried out in a vessel starting with partial pressure P_SO2 = 250 m bar, P_O2 = 750 m bar and P_SO3 = 0 bar. When the reaction is complete, the total pressure in the reaction vessel is _______ m bar. (Round off of the nearest integer).

10.0 mL of 0.05 M KMnO₄ solution was consumed in a titration with 10.0 mL of given oxalic acid dihydrate solution. The strength of given oxalic acid solution is _________ $$\times$$ 10^$$-$$2 g/L.

(Round off to the nearest integer)

The total number of electrons in all bonding molecular orbitals of $$O_2^{2 - }$$ is ______________.

(Round off to the nearest integer)