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 $(1 \ L \ atm = 101.3 \ J)$:

$A$ gas occupies $2 \ L$ at $S.T.P.$ It is supplied with $300 \ J$ of heat,causing its volume to expand to $2.5 \ L$ against an external pressure of $1 \ atm$. What is the change in internal energy in $J$?

For an ideal gas,the heat of reaction at constant pressure and heat of reaction at constant volume are related by the equation:

Which of the following statements is correct?

$A$ system receives $224 \ J$ of heat and does $156 \ J$ of work. Calculate the change in internal energy. (in $J$)

Assuming that water vapour is an ideal gas,the internal energy change $(\Delta U)$ when $1\, mol$ of water is vaporised at $1\, bar$ pressure and $100\, ^{\circ}C$,(given: molar enthalpy of vaporisation of water at $1\, bar$ and $373\, K = 41\, kJ\, mol^{-1}$ and $R = 8.3\, J\, mol^{-1}\, K^{-1}$) will be .............. $kJ\, mol^{-1}$