Welcome :: Homework Help and Answers :: Mathskey.com

Recent Visits

    
Welcome to Mathskey.com Question & Answers Community. Ask any math/science homework question and receive answers from other members of the community.

13,435 questions

17,804 answers

1,438 comments

774,936 users

Reaction mechanisms?

0 votes

Example 1: Consider the following reac<on:
2 NO(g) + Br
2(g) → 2 NOBr(g)

(a) Write the rate law for the reaction, assuming it involves a single elementary reaction. (b) Is a single step mechanism likely for this reaction?

Example 2; A reaction is believed to occur in two steps:

O3 + NO2--> NO3 + O2

NO3 + NO2 --> N2O5

 (a) Write the overall reaction. (b) The experimental rate law is rate = k[O3][NO2]. What can you say about the relative rates of the two steps of the mechanism. 

 

 

asked Mar 1, 2015 in CHEMISTRY by heather Apprentice

2 Answers

0 votes

Step 1:

Example 1:

(a)

The chemical equation is image.

Single elementary reaction:

Every reaction is made up of one or more elementary steps.

Rate law of the elementary reaction depends on the concentration of reactants only.

For example, image is a elementary reaction,

then rate law of the reaction is defined by image.

Rate law of the reaction image is image.

Step 2:

(b)

The chemical equation is image.

The reaction is a termolecular reaction.

termolecular reaction requires the collision of three particles at the same place and time.

A termolecular reaction is a very rare reaction as the three molecules reacting at same time is unlikely.

Hence the single step mechanism for this reaction is unlikely.

Solution:

(a) Rate law of the reaction is image.

(b) The single step mechanism for this is unlikely because it is a termolecular reaction.

answered Mar 2, 2015 by Lucy Mentor
edited Mar 2, 2015 by Lucy
0 votes

Step 1:

Example 2:

(a)

The reaction is taken in two steps:

image

Add the two elementary reactions.

As appears in equal amount on the both sides of the reaction, it can be eliminated.

The net equation is .

Hence, the overall reaction is .

Step 2:

(b)

The step 1 reaction is slow reaction and step 2 reaction is the fast step reaction.

 The rate determining step is rate of reaction of step 1.

Rate law of the reaction of step 1 is image.

Hence, the rate of reaction of the overall reaction is image.

Solution:

(a) The overall reaction is .

(b) The rate of reaction of the overall reaction is image.

answered Mar 2, 2015 by Lucy Mentor

Related questions

asked Oct 1, 2015 in CHEMISTRY by anonymous
...