$A$ system does $394 \ J$ of work on the surroundings by absorbing $701 \ J$ of heat. What is the change in internal energy of the system (in $J$)?

An isolated chamber is divided into two halves by a partition,with an ideal gas in one half. By making a hole in the partition,the gas is allowed to expand to the full chamber. Among the following,the parameter which changes in the process is

$A$ gas is allowed to expand in a well-insulated container against a constant external pressure of $2.5 \ atm$ from an initial volume of $2.50 \ L$ to a final volume of $4.50 \ L$. The change in internal energy $\Delta U$ of the gas in joules will be .............. $J$.

The temperature of a system decreases in which of the following processes?

The $\Delta U^o$ of combustion of $CH_{4(g)}$ at a certain temperature is $-393 \ kJ/mol$. Then the value of $\Delta H^o$ is:

Joule-Thomson expansion is: