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Chemistry: Post your doubts here!

Thought blocker

Thought blocker

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Tulaib said:
Can anyone solve Q9?
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_11.pdf
Click to expand...
Easiest approach I would use is to do trial and error with the 4 options, which is fast after some practice.
Since B is the answer, I'll use it as example

2P --> 2Q+ R
2.........0 .....0 ..... initial
-2x ...... +2x .... +x ..change
2-2x..... 2x ..... x..... final

Refer to the steps below if you are not sure how the info in the above table is filled up.
1st step : write down info for the initial row
2nd step write down that R will be x moles as stated in question
3rd step: fill in the info in green
4th step: fill in the info in yellow
5th step: fill in the row for final
Check that the info in the final step adds up to 2 + x . ( 2 -2x + 2x + x )
 
B

Browny

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http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_s06_qp_1.pdf
Can anybody please explain questions 22, 31? Ans are A and B respectively.

In 22 why can't B be the correct answer and in 31 can you explain the 1 statement.
Also in a reaction pathway involving a intermediate is the first stage Ea always greater than the second stage Ea?

http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_w06_qp_1.pdf
Can anybody please explain questions 5, 19? Ans are B and B respectively.

THANKS IN ADVANCE!:)
 
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