Questions $6.$ A simple case of a series reaction is illustrated below:

$A_1{r}_1{A}_2{r}_2{A}_3$

Assuming an approach of first$-$order rate equation of the following type: $r_1=k_1{C}_{A1}$;$r_2=k_2{C}_{A2}.$ The initial concentrations of the three components are: $C_{A1}^0=1$;$C_{A2}^0=C_{A3}^0=0.$ Write the mass balance equations of each component and solve the equations. Draw the graph of concentrations A$1,$ A$2,$ A$3$ versus time.