## Quiz Prep Question

$aR \to bP, Rate = -\frac{1}{a} \frac{d[R]}{dt} = \frac{1}{b}\frac{d[P]}{dt}$

Kira Conde 2O
Posts: 24
Joined: Fri Jul 15, 2016 3:00 am

### Quiz Prep Question

Hi,

I found this question in an old quiz prep book and I'm not sure how to do it. It reads:

When 420 mg of NO2 is confined to a 150 ml reaction vessel and heated to 300 C it decomposes by a second order process with the rate of k= 0.54 l/mol/s. What is its initial rate? By what factor will the rate increase if the initial concentration is changed by 1.68 grams?

I honestly don't even know where to start! Please help!

Jessica Huang 1M
Posts: 26
Joined: Wed Sep 21, 2016 2:59 pm

### Re: Quiz Prep Question

second order process means that rate=k[NO2]^2

must find [NO2]: 0.42 g NO2*(mol NO2/46 g)/0.15 L = 0.06087 mol NO2/L

rate= k[NO2]^2
=(0.54 L/mol/s)* (0.06087 mol NO2/L)^2 = 0.0020 mol/l/s = initial rate

For second part of the question, repeat above process with new initial amount of NO2 and then compare your new rate with your old rate.