$A$ thermos flask containing some ice cubes is sealed tightly. This is an example of which type of system?

The evaporation of water is a:

What is molar enthalpy of vaporization?

For which of the following reactions is $\Delta E = \Delta H$?

In a reversible isothermal process,the change in internal energy is

$A$ certain mass of a gas was brought from state $A$ to $B$ by following three different paths,namely $1$,$2$ and $3$,respectively. Which of the following relations is correct for the work done?