The workdone by $0\mathrm{.}07kg$ of air when it expands according to $p{v}^n=$ Constant is $7\mathrm{.}6kJ.$ The

temperature of air falls from an initial value of $105C$ to a final value of $13C$ during the process. Determine :

the heat supplied or rejected by the air during the expansion ; $2$ the value of index $n$; and $3.$ the change of

entropy, stating whether this is an increase or decrease. $=1\mathrm{.}4$ and $c_v=0\mathrm{.}712k\frac{J}{k}gK.$

$[$Ans$.3kJ$;$1\mathrm{.}24$;$0\mathrm{.}00926k\frac{J}{K}($increase$)]$