k = 1;
cA0 = 1;
cA1 = (1/((1/cA0^2) + 
                  8*k*t))^0.5;
cA2 = (1/((1/cA0^2) + 
                  2*k*t))^0.5;
Plot[{cA1, cA2}, {t, 0, 2},  
        PlotStyle ->  {Thickness[0.005], 
            Thickness[0.008]}];

Note that the cA vs. time curve for constant rxn order but different stoichiometries is simply shifted w/r to the y-axis.
This is in contrast to the case (see file Analysis of n-th Order Rxn) where cA vs. time curves are plotted for constant rxn stoichiometry but different rxn orders.