$16 \ g$ of oxygen gas expands isothermally and reversibly at $300 \ K$ from $10 \ dm^3$ to $100 \ dm^3$. The work done is (in $J$ )

An ideal gas expands against a constant external pressure of $2 \ bar$ from $5 \ L$ to $8 \ L$ and absorbs $10 \ kJ$ of heat. What is $\Delta U$ of the system (in $J$)?

Consider the reaction: $N_2(g) + 3H_2(g) \to 2NH_3(g)$ carried out at constant temperature and pressure. If $\Delta H$ and $\Delta U$ are the enthalpy and internal energy changes for the reaction,which of the following expressions is true?

What is the change in internal energy if a system gains $x \ J$ of heat and $y \ J$ of work is done on it?

Which of the following statements is appropriate as per the first law of thermodynamics?

Calculate the change in internal energy of the system if work done by the system is $18 \ J$ and absorbs heat $50 \ J$ in a particular reaction. (in $J$)