For the reaction $CaCO_{3(s)} \rightarrow CaO_{(s)} + CO_{2(g)}$ at $977 \, ^\circ C$,$\Delta H = 174 \, kJ/mol$. Calculate $\Delta U$ in $kJ$.

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 $J$)?

For the gaseous reaction $A_{(g)} + 3B_{(g)} \rightarrow 3C_{(g)} + 3D_{(g)}$,the value of $\Delta U = 17 \, Kcal$ at $27 \, ^oC$. Assuming $R = 2 \, cal \, K^{-1} \, mol^{-1}$,the value of $\Delta H$ for the above reaction will be ....... $Kcal$.

The first law of thermodynamics for an isothermal process is:

Which of the following is the correct expression of the first law of thermodynamics for adiabatic processes?

$5 \, mol$ of an ideal gas expands isothermally and irreversibly from a pressure of $10 \, atm$ to $1 \, atm$ against a constant external pressure of $1 \, atm$. The work done $(w_{irr})$ at $300 \, K$ is: