2.2 g of nitrous oxide $\left({\mathrm{N}}_2\mathrm{O}\right)$ 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 167.75 mL. The change in internal energy of the process, $\mathrm{\Delta U}$ is ‘-x’ J. The value of 'x ' is_________. [nearest integer]

$\text{ (Given: atomic mass of }\mathrm{N}=14{\mathrm{gmol}}^{-1}\text{ and of }\mathrm{O}=16{\mathrm{gmol}}^{-1}\text{. Molar heat capacity of }{\mathrm{N}}_2\mathrm{O}\text{ is }100{\mathrm{JK}}^{-1}{\mathrm{mol}}^{-1}\text{ ) }$