We formulate a least squares function in the constants (now variables) k1 and k2 using the data from the chemical b.

Input := 


SSb[k1_,k2_] = Sum[(bsol[bdata[[n,1]]] -  bdata[[n,2]])^2,

                 {n,1, Length[bdata]}];

Input := 


solbk = FindMinimum[SSb[k1,k2],{k1,.1},{k2,.2}]

Output =


{1.00015, {k1 -> 0.0623575, k2 -> 0.0210941}}