A certain gaseous mixture is composed of $140$ moles of $A,170$ moles of $B,$ and $90$ moles of $C.$ The mixture is heated from $30C$ to $50C$ at constant pressure. Determine the change in entropy in kj$/$k$).$

Heat capacities of the components are as follows:

$A=43\frac{j}{m}ol-K$

$B=54\frac{j}{m}ol-K$

$C=11\frac{J}{m}ol-K$