$A$ well-stoppered thermos flask contains some ice cubes. This is an example of a

When a system goes from state $A$ to state $B$,the change in internal energy is $40 \, kJ/mol$. If the system returns from state $B$ to state $A$ via a reversible path and then returns to state $A$ via an irreversible path,what is the net change in internal energy?

On what factors does the enthalpy of dilution of a solution depend?

Identify the correct statements from the following:
$I$) Work is a path function.
$II$) Enthalpy is an extensive property.
$III$) Lattice enthalpy of ionic compounds can be obtained from Born-Haber cycle.

If the work done by $2 \ mol$ of an ideal gas during isothermal reversible expansion from $5 \ L$ to $50 \ L$ is $-189.1 \ L \ atm$,the temperature of the gas (in $^{\circ}C$) is

For which of the following reactions,$\Delta H$ is equal to $\Delta U$ ?