The change in internal energy $\Delta U$ of an ideal gas depends on:

For which of the following systems, the difference between $\Delta H$ and $\Delta U$ is not significant?
$(i)$ Solids
$(ii)$ Gases
$(iii)$ Mixture of gases and liquids
$(iv)$ Liquids

Fill in the blanks:
$(i)$ $A$ system that allows the exchange of energy but not matter with the surroundings is called a ........ .
$(ii)$ The total amount of energy consisting of the internal energy of a substance plus the product of its pressure and volume is called ........ .
$(iii)$ The change in energy that occurs when a chemical reaction is carried out at constant pressure is called ........ .

The number of extensive properties in the following list is: enthalpy,density,volume,internal energy,temperature.

In an endothermic reaction,the value of $\Delta H$ is

When $2$ moles of an ideal gas are expanded isothermally from a volume of $12.5 \ L$ to $15.0 \ L$ against a constant external pressure of $760 \ mm \ Hg$,calculate the amount of work done in joules. (in $J$)