$ = 300\,{\left\{ {{{\left( {\frac{{27}}{8}} \right)}^{1/3}}} \right\}^2} = 800\,{\left( {\frac{3}{2}} \right)^2} = 675K$
$ \Rightarrow \;\Delta T = 675 - 300 = 375\;K$


Statement $2 :$ The temperature of a gas remains constant in an adiabatic process.
