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Chemistry Paper 4-theory- doubts =D

knowitall10

knowitall10

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Can someone please post the link to the winter 11 examiner's report?
Jazakum Allahu Khair.
 
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PhyZac

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knowitall10 said:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w11_qp_41.pdf

Q 2(a)
Can somebody please tell me how to calculate the order with respect to H+??
Thank you very much.
Jazakum Allahu Khair!
Click to expand...
Okay, see
We know that order of reaction of CH3CHO is one
so since it decrease from
0.25 to 0.2
so 0.25/0.2
=5/4
so basically the rate, must have decrease from 2 to 1.6 (2 x 4/5)

now we consider the change due to H is from 1.6 to to 3.2
and 3.2/1.6 is 2
and 0.1/0.05 is 2
so order is 1
 
knowitall10

knowitall10

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PhyZac said:
Okay, see
We know that order of reaction of CH3CHO is one
so since it decrease from
0.25 to 0.2
so 0.25/0.2
=5/4
so basically the rate, must have decrease from 2 to 1.6 (2 x 4/5)

now we consider the change due to H is from 1.6 to to 3.2
and 3.2/1.6 is 2
and 0.1/0.05 is 2
so order is 1
Click to expand...
Jazak Allahu Khair!:):)
But how did you get 1.6?
 
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sagar65265

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knowitall10 said:
or anyone online....please...
Click to expand...


If it is the one where you have to state the units of the rate constant, then:

The units of rate of reaction mol dm^-3 s^-1.
The reaction is first order with respect to each reactant involved, so to ensure that the units on the left of the equation are equal to the units on the right side,

mol dm^-3 s^-1 = k * (mol dm^-3)(mol dm^-3)(mol dm^-3)

Cancelling units from both sides,

s^-1 = k * (mol dm^-3)(mol dm^-3)

Rearranging for k,

mol^-2 dm^6 s^-1 = k

Therefore the units of the rate constant are mol^-2 dm^6 s^-1.

Hope this helped!
Good Luck for all your exams!
 
knowitall10

knowitall10

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sagar65265 said:
If it is the one where you have to state the units of the rate constant, then:

The units of rate of reaction mol dm^-3 s^-1.
The reaction is first order with respect to each reactant involved, so to ensure that the units on the left of the equation are equal to the units on the right side,

mol dm^-3 s^-1 = k * (mol dm^-3)(mol dm^-3)(mol dm^-3)

Cancelling units from both sides,

s^-1 = k * (mol dm^-3)(mol dm^-3)

Rearranging for k,

mol^-2 dm^6 s^-1 = k

Therefore the units of the rate constant are mol^-2 dm^6 s^-1.

Hope this helped!
Good Luck for all your exams!
Click to expand...
Right!! Jazak Allahu Khairan! Yes it has!:)
May Allah bless you!
Thank you! Good Luck to you too inshAllah:):)
 
Arpit17

Arpit17

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sagar65265 said:
If it is the one where you have to state the units of the rate constant, then:

The units of rate of reaction mol dm^-3 s^-1.
The reaction is first order with respect to each reactant involved, so to ensure that the units on the left of the equation are equal to the units on the right side,

mol dm^-3 s^-1 = k * (mol dm^-3)(mol dm^-3)(mol dm^-3)

Cancelling units from both sides,

s^-1 = k * (mol dm^-3)(mol dm^-3)

Rearranging for k,

mol^-2 dm^6 s^-1 = k

Therefore the units of the rate constant are mol^-2 dm^6 s^-1.

Hope this helped!
Good Luck for all your exams!
Click to expand...
what about b(i) and (ii)??
 
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