[thejollyfroggie]

How do I find the rate constant when the problem gives me the initial concentration of one of the reactants and the concentration changes of the other reactant with respect to time in a reaction run at 25 Celsius? Both reactants are first order. And if the rate law has to be integrated, how do I go about doing that in this case?

rate law:
v= k[A]^1[B ]^1

Initial [A] (which I call [A]0) is 0.04 M in reaction at 25 Celsius. [B ] is 0.105, 0.092, 0.084, 0.075, 0.067 M at 0, 1000, 2015, 6000, and 11500 seconds respectfully. What is the rate constant? I know that when the two reactans have different initial concentrations, the rate law for a second order reaction is: kt=(1/([B ]0[A]0))ln ([B ]0[A]/[A]0[B ]) but I don't really know what to do. Any help would be great, thanks.

[Kadabrium]

if you still find the exprssion too complcted after integration,
 try to take a logarithm of that..