## 15.3

josephyim1L
Posts: 61
Joined: Fri Sep 28, 2018 12:15 am

### 15.3

Can someone explain this to me:

15.3 In 20. s, the concentration of nitrogen dioxide, NO2, decreases from 450 mmol/L to 320 mmol/L in the reaction 2 NO2(g) 2 NO(g) O2(g). (a) Determine the rate of reaction of NO2. (b) Determine the rate of formation of O2.
(c) What is the unique rate of the reaction?

Samantha Man 1L
Posts: 63
Joined: Fri Sep 28, 2018 12:22 am

### Re: 15.3

You use the average rate of rxn equation where you do -delta(R)/delta(t). And then you look at the coefficients to find the ratios and the rates of each compound.

Lynsea_Southwick_2K
Posts: 55
Joined: Fri Sep 28, 2018 12:25 am

### Re: 15.3

Do you work backwards for part c? I am not sure what to do.
I have the rate of reaction of NO2, I know the coefficient of NO2 is 2.
Do I divide 6.5 x 10^-3 by 2? How does that give the unique rate of the whole reaction?

Parth Mungra
Posts: 72
Joined: Fri Sep 28, 2018 12:28 am

### Re: 15.3

You do not need to work backward from part c. You can find the average change in rate (part a) by dividing the change in concentration by the change in time. Part B is asking about ratios of rates, which can be found by looking at stoich. coefficients. Thus, you can find part c based on these coefficients.