Calculate the work done when $1$ mole of an ideal gas is expanded reversibly and isothermally from initial pressure $10$ bar to final pressure $1$ bar at constant temperature $300$ K. [$R = 8.314 \text{ J K}^{-1} \text{ mol}^{-1}$]

Which of the following processes exhibits, $\Delta U = 0$?

Which of the following aqueous solution of salt have $pH < 7$ at $298$ K?

What happens when solid $\text{Na}_2\text{CO}_3$ dissolved in water?