When certain volume of gas expands against a constant external pressure of $$2.40 \times 10^5 \mathrm{~Pa}$$ at 300 $$\mathrm{K}$$ to $$2.2 \times 10^{-3} \mathrm{~m}^3$$. If the work obtained is $$-0.048 \mathrm{~kJ}$$. What is the initial volume of the gas?

Which among the following pairs of electronic effect and it's example is NOT correct?

A certain mass of a gas occupies volume of 250 mL at 2 atm. Calculate the volume of gas if pressure is increased to 2.5 atm at constant temperature.

Vapour pressure of solution and of pure solvent are $$\mathrm{P}_1$$ and $$\mathrm{P}_1{ }^0$$ respectively. If $$\frac{P_1}{P_1^0}$$ is 0.15, find the mole fraction of solute.