Two moles of an ideal gas are expanded isothermally from $$15 \mathrm{dm}^3$$ to $$20 \mathrm{dm}^3$$. If the amount of work done is $$-6 \mathrm{dm}^{-3}$$ bar, find external pressure needed to obtain this work.

Find the value of $$-197^\circ$$C temperature in Kelvin.

A gas is allowed to expand in an insulated container against a constant external pressure of 2.5 atm from $$2.5 \mathrm{~L}$$ to $$4.5 \mathrm{~L}$$, the change in internal energy of the gas in joules is

What is the work done when a gas is compressed from 2.5 $$\times$$ 10$$^{-2}$$ m$$^3$$ to 1.3 $$\times$$ 10$$^{-2}$$ m$$^3$$ at constant external pressure of 4.05 bar?