A gaseous mixture that is $35\%$ propane $($C$3$H$8)$ and $65\%$ methane $($CH$4)$ by volume is mixed with

$25\%$ excess air and burned in a steady$-$state constant pressure process at $100$ kPa. Both the fuel and

the air enter the combustion chamber at $298$K and undergo a complete combustion process. The

products leave the combustion chamber at $450$K$.$ If the mass flow rate of the air is $50$ kg$/$hr$,$ calculate

the rate of heat transfer for the process.