An ice cube placed in an ideal thermos flask represents a/an ...... system.

Choose the correct answer. $A$ thermodynamic state function is a quantity

Two moles of an ideal gas expand freely and isothermally from $5 \ dm^3$ to $50 \ dm^3$. What is the value of $\Delta H$?

Fill in the blanks:
$(i)$ During the ........... process,there is no absorption or evolution of heat.
$(ii)$ The equation $\Delta G = \Delta H - T\Delta S$ was proposed by ........... .

When the temperature of $2$ moles of an ideal gas is increased by $20^{\circ} C$ at constant pressure,find the work involved in the process. (in $R$)

For the reaction of nitrogen with hydrogen to form ammonia,$\Delta H^o = -92.2 \ kJ/mol$. If the reaction is carried out at a constant pressure of $20.0 \ atm$ and a volume change of $-1.16 \ L$,calculate the change in internal energy $(\Delta U)$ in $kJ$.