.06 mole
- Bitan Chakraborty No................
Hint:
[B]>>[A], hence, rate is dependent on A,ie, 1st order w.r.t A.Upvote·0· Reply ·2013-04-22 23:04:34
A certain reaction A + B â†’ Product is first-order w.r.t. each reactant with k = 5.0 x 10^{-3} M^{-1}s^{-1}. Calculate the concentration of A remaining after 100 s if the initial concentration of A was 0.1 M and that of B was 6.0 M. State any approximation made in obtaining your result.
.06 mole
Dada first see whether my approach is correct or not......
-d[A]/dt=k[A] (As the reaction is first order w.r.t A and B is present in excess)
Given,the initial concentration of A is 0.1M.Let the final concentration be xM.
A.T.P
âˆ«d[A]/[A]=-âˆ«k.dt (Integration limit for [A] is from 0.1 to x and integration limit for time is from 0 to 100 secs)
After integrating we get,
log[x]-log(0.1)=-5*10^-1
[x]=10^-3/2........whether this is correct????
Since [B] = 6.0, we can consider that its concentration remains constant throughout.
Thus, rate = k[A][B] = 6k[A] = k ^{/}[A]
where, k ^{/} ( = 6k ) is the new constant and reaction under this condition is supposed to follow 1st order kinetics.
k ^{/} = 2.303t log (aa-x)
Now putting in the values we have,
aa-x = 20
So that (a-x) = 0.005 M