For the reaction A+B==>AB, the following data were obtained

Question

For the reaction A+B==>AB, the following data were obtained

 

Trial 1

Initial  [A]=0.480 Initial  [B]=0.190 Initial rate= 0.350

 

Trial 2

[A]=0.480. [B]=0.380 initial rate=0.350

 

Trial 3

 

[A]=0.240 [B]=0.190 initial rate=0.087

 

A. Determine the order with respect to each reactant 

B. Determine the overall order of the reaction

 

C. Write the rate expression for the reaction 

 

D. Find the value  of the rate constant , k.

Answer 1

A.  Comparing trial 3 to trial 1: [A] doubles and [B] remains same and rate by 4 times (0.350/0.087).  This means it is 2nd order with respect to A.

Comparing trial 1 to trial 2: [B] double and [A] remains same and rate stays same (0.350 each time). This means it is zero order with respect to B.

 

B.  The overall order is 2 + 0 = 2

 

C.  Rate expression is rate = k[A]²

 

D.  rate = k[A]²

0.350 = k[0.48]²

0.350 = 0.2304k

k = 1.52 units will depend on units used for rate, and will be of the type M^-1s^-1 for 2nd order reaction.