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

For an exothermic reaction,

The evaporation of water is a:

$X$ is an extensive property and $x$ is an intensive property of a thermodynamic system. Which of the following statement$(s)$ is (are) correct?

Two moles of an ideal gas expand spontaneously into a vacuum. The work done is ............. $Joule$.

Two moles of an ideal gas are compressed isothermally and reversibly from $40 \ L$ to $20 \ L$ at $300 \ K$. What is the work done (in $kJ$)? $(R=8.314 \ J \ K^{-1} \ mol^{-1})$