Question

The reaction between A and B is first order with respect to A and zero order with respect to B. Fill in the blanks in the following table:

Experiment	A/ mol L -1	B/ mol L -1	Initial rate/mol L -1 min-1
I	0.1	0.1	2.0x10-2
II	-	0.2	4.0x10-2
III	0.4	0.4	-
IV	-	0.2	2.0x10-2

Answer 1

The given reaction is of the first order with respect to A and of zero order with respect to B.
Therefore, the rate of the reaction is given by,
Rate = k [A]1[B]0
⇒ Rate = k[A]
From experiment I, we obtain
2.0 x 10-2 mol L-1min-1= k (0.1 mol L-1)
⇒ k= 0.2 min-1
From experiment II, we obtain
4.0 x 10-2 mol L-1min-1= 0.2 min-1[A]
⇒ [A] = 0.2 mol L-1
From experiment III, we obtain
Rate = 0.2 min-1 x 0.4 mol L-1
= 0.08 mol L-1 min-1
From experiment IV, we obtain
2.0 x 10-2 mol L-1 min-1= 0.2 min-1 [A]
⇒ [A] = 0.1 mol L-1