For the reaction $CO_{(g)} + \frac{1}{2} O_{2(g)} \to CO_{2(g)}$,which of the following is true?

$A$ sample of gas absorbs $4000 \ kJ$ of heat and the surrounding does $2000 \ J$ of work on the sample. What is the value of $\Delta U$ (in $kJ$)?

For the exothermic reaction of $1 \ mol$ of $Zn$ dust with $1 \ mol$ of $H_2SO_4$ in a bomb calorimeter,the relationship between $\Delta U$ and $w$ is .....

$A$ gas is allowed to expand in an insulated container against a constant external pressure of $2.5 \ atm$ from $2.5 \ L$ to $4.5 \ L$. The change in internal energy of the gas in joules is: (in $J$)

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 $J$)?

The volume of an ideal gas contracts from $10.0 \ L$ to $2.0 \ L$ under an applied pressure of $2.0 \ atm$. During contraction,the system also evolved $900 \ J$ of heat. The change in internal energy (in $J$) involved in the system is $(1 \ L \ atm = 101.3 \ J)$: