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# Orders of Reaction?

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1. Attachment 585030585032Hi,

I really don't understand orders of reaction and rate equations. Could someone have a look at the attached pictures and see if I'm on the right track?

Thanks,
Blake

Attachment 585030585032585100[attach]5.8503058503258506e+23[/attach]
Attached Images

2. (Original post by Blake Jones)
Attachment 585030585032Hi,

I really don't understand orders of reaction and rate equations. Could someone have a look at the attached pictures and see if I'm on the right track?

Thanks,
Blake

Attachment 585030585032585100[attach]5.8503058503258506e+23[/attach]
First things first I would work out the relative concentrations of the components in the three expts, bearing in mind that the volume in expt 1 is 400 ml while the volume in 2 & 3 is 200 ml

So between expts 1 & 2 bromate and bromide ion concentrations are constant, therefore the fourfold increase is due to hydrogen ion concentration, which doubles.

Therefore the order wrt [H+] = 2

Between expts 2 & 3 bromide and hydrogen ions are constant, but bromate ions double in concentration and the rate doubles. Hence order wrt Bromate = 1

Between expts 1 and 3 bromate ions and hydrogen ionhs double and the rate increases by a factor of 8.

We have already established that doubling the H+ ion concentration will increase the rate by a factor of four, so the extra factor of two must be due to bromate. Hence order wrt bromate = 1

Rate = k[BrO3-]1[Br-]1[H+]2
3. (Original post by charco)
First things first I would work out the relative concentrations of the components in the three expts, bearing in mind that the volume in expt 1 is 400 ml while the volume in 2 & 3 is 200 ml

So between expts 1 & 2 bromate and bromide ion concentrations are constant, therefore the fourfold increase is due to hydrogen ion concentration, which doubles.

Therefore the order wrt [H+] = 2

Between expts 2 & 3 bromide and hydrogen ions are constant, but bromate ions double in concentration and the rate doubles. Hence order wrt Bromate = 1

Between expts 1 and 3 bromate ions and hydrogen ionhs double and the rate increases by a factor of 8.

We have already established that doubling the H+ ion concentration will increase the rate by a factor of four, so the extra factor of two must be due to bromate. Hence order wrt bromate = 1

Rate = k[BrO3-]1[Br-]1[H+]2

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