Question

Consider the following reaction:

NO2(g)→NO(g)+1/2O2(g)

The following data were collected for the concentration of NO2 as a function of time:

Time (s)(s)	[NO2][NO2] (M)(M)
0	1.000
10	0.951
20	0.904
30	0.860
40	0.818
50	0.778
60	0.740
70	0.704
80	0.670
90	0.637
100	0.606

What is the rate of formation of O2 between 50 and 60 s?

Express your answer to two significant figures.

Answer 1

Rate of the reaction

= - = 2

Or, = -   

Now,

From the table

Rate of disappearance of NO₂ between 50 to 60 s

= -

= -

= 0.0074 M/s.

So,

Rate of formation of O₂ between 50 and 60 s

= - ×

=   × (0.0074) M/s

= 0.0037 M/s.

= 3.7 × 10^-3 M/s ( 2 significant figures) .