If $65 \ kJ$ of work is done on the system and it releases $25 \ kJ$ of heat,what is the change in internal energy of the system (in $kJ$)?

An ideal gas absorbs $210 \ J$ of heat and undergoes expansion from $3 \ L$ to $6 \ L$ against a constant external pressure of $10^5 \ Pa$. What is the value of $\Delta U$ (in $J$)?

If $\Delta H$ is the change in enthalpy and $\Delta E$ is the change in internal energy accompanying a gaseous reaction,which of the following is true?

When $100 \ cal$ of heat is supplied to a system,the work done by the system is $300 \ J$. The change in internal energy of the system is ..... $J$.

Calculate the difference between $\Delta H$ and $\Delta U$ for the combustion of $n$-octane at $25^{\circ}C$. (in $kJ$)

$A$ mixture of $2 \ mol$ of $CO_{(g)}$ and $1 \ mol$ of $O_{2(g)}$ is ignited to convert $CO$ to $CO_2$. Which of the following relations is correct?