A2 Chemistry rate of reaction and orders help

username1482097

Badges: 6

Rep:

#1

Report Thread starter 4 years ago

#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.

Thanks in advance.

0

reply

Kill3er

Badges: 13

Rep:

#2

Report 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

reply

Don Pedro K.

Badges: 9

Rep:

#3

Report 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

reply

Kill3er

Badges: 13

Rep:

#4

Report 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

reply

Don Pedro K.

Badges: 9

Rep:

#5

Report 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

reply

Kill3er

Badges: 13

Rep:

#6

Report 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

reply

Quick Reply

Oops, nobody has posted
in the last few hours.

See more of what you like on
The Student Room

Today on TSR

University open days

Poll

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

Watched Threads

Oops, nobody has posted
in the last few hours.

See more of what you like on
The Student Room

TSR Support Team

Get Started

Using TSR

Info

TSR Group

Connect with TSR

A2 Chemistry rate of reaction and orders help Watch

Not what you're looking for? Try…

Quick Reply

Related discussions

Related articles

Oops, nobody has postedin the last few hours.

Oops, nobody is replying to posts.

See more of what you like onThe Student Room

Today on TSR

University open days

Poll

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

Watched Threads

Spotlight

Oops, nobody has postedin the last few hours.

Oops, nobody is replying to posts.

See more of what you like onThe Student Room

TSR Support Team

Get Started

Using TSR

Info

TSR Group

Connect with TSR

Oops, nobody has posted
in the last few hours.

See more of what you like on
The Student Room

Oops, nobody has posted
in the last few hours.

See more of what you like on
The Student Room