The change in internal energy equals

When $x \ kJ$ heat is provided to a system,work equivalent to $y \ J$ is done on it. What is the internal energy change during this operation?

During an isothermal process,which of the following is true?

For the reaction $C_2H_5OH_{(l)} + 3O_{2(g)} \rightarrow 2CO_{2(g)} + 3H_2O_{(l)}$,the enthalpy change $(\Delta H)$ at $27\,^oC$ is $-1366.5 \,kJ\,mol^{-1}$. What will be the value of the internal energy change $(\Delta U)$ in $kJ\,mol^{-1}$ at the same temperature?

$A$ gas absorbs $120 \text{ J}$ of heat and expands by $300 \times 10^{-6} \text{ m}^3$ against a constant external pressure of $2 \times 10^5 \text{ Nm}^{-2}$. What will be the change in internal energy of the system (in $\text{ J}$)?

Based on the first law of thermodynamics,which of the following is correct?