2 g of nitrous oxide ( N_2 O ) gas is cooled at a constant pressure of 1 atm from 310 K to 270 K causing the compression of the gas from 217.1 mL to…

$\displaystyle 2$ g of nitrous oxide $\displaystyle \left(\mathrm{N}_2 \mathrm{O}\right)$ gas is cooled at a constant pressure of $\displaystyle 1$ atm from $\displaystyle 310$ K to $\displaystyle 270$ K causing the compression of the gas from $\displaystyle 217.1$ mL to $\displaystyle 167.75$ mL . The change in internal energy of the process, $\displaystyle \Delta \mathrm{U}$ is '$\displaystyle -\mathrm{x}$' J. The value of ' x ' is \_\_\_\_. [nearest integer] (Given: atomic mass of $\displaystyle \mathrm{N}=14 \mathrm{~g} \mathrm{~mol}^{-1}$ and of $\displaystyle \mathrm{O}=16 \mathrm{~g} \mathrm{~mol}^{-1}$. Molar heat capacity of $\displaystyle \mathrm{N}_2 \mathrm{O}$ is $\displaystyle 100 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$ )