# A2 Chemistry rate of reaction and orders helpWatch

#1
Rate equation of this reaction is: rate = k[B][C]2

The original rate of reaction is 6.5 (mol dm-3 s-1) what would the new rate be if B was doubled and C was tripled at the same time.

0
4 years ago
#2
Well B is first order and C is second order.

Doubling B doubles the rate (*2)
Tripling C multiple the rate by 3^2 (*9)

So multiply the rate by 2 and then multiply the answer by 9.
0
4 years ago
#3
(Original post by Kill3er)
Well B is first order and C is second order.

Doubling B doubles the rate (*2)
Tripling C multiple the rate by 3^2 (*9)

So multiply the rate by 2 and then multiply the answer by 9.
I just did this stuff today for the first time, but I agree with what Mr. Kill3er has said here except for one thing; surely the tripling the concentration of C would result in the rate increasing by 2^3 and the other way round? So multiply by 8 instead of 9? I may be wrong but this is what I thought...
0
4 years ago
#4
(Original post by Don Pedro K.)
I just did this stuff today for the first time, but I agree with what Mr. Kill3er has said here except for one thing; surely the tripling the concentration of C would result in the rate increasing by 2^3 and the other way round? So multiply by 8 instead of 9? I may be wrong but this is what I thought...
Second order is squaring. Just finished A2
0
4 years ago
#5
(Original post by Kill3er)
Second order is squaring. Just finished A2
Ohh okay Thanks for the clarification! How did you find A2 chem? I'm with Edexcel and I found As relatively easy; the exams in particular (I think I got around 73/80 give or take a couple of marks on both papers).
0
4 years ago
#6
(Original post by Don Pedro K.)
Ohh okay Thanks for the clarification! How did you find A2 chem? I'm with Edexcel and I found As relatively easy; the exams in particular (I think I got around 73/80 give or take a couple of marks on both papers).
I'm with aqa. It wasn't too bad. Lots of colours to memorise for transition metals.
0
X

new posts
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### University open days

• Bournemouth University
Wed, 31 Jul '19
• Staffordshire University
Wed, 7 Aug '19
• University of Derby
Foundation Open Event Further education
Wed, 7 Aug '19

### Poll

Join the discussion

#### Are you tempted to change your firm university choice on A-level results day?

Yes, I'll try and go to a uni higher up the league tables (164)
17.45%
Yes, there is a uni that I prefer and I'll fit in better (82)
8.72%
No I am happy with my course choice (560)
59.57%
I'm using Clearing when I have my exam results (134)
14.26%