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# Kinetics A2. I AM IN URGENT NEED OF HELP! I HAVE BROKEN TWO BIRO PENS IN ANGER! watch

1. I've been trying question 1.a) for one hour and a half...ONE HOUR AND A HALF AND ITS ONLY WORTH 3 ******* MARKS I'm so upset that i can't do this I'm about to cry. I don't know why I can't get it. How can you do a 3 mark question for more than an hour? Am I that stupid, really?

I found the order with respect to [B] = 1. I can't find [A] or [C]. My teacher taught us to add an extra row. please can someone help me/teach me? i'm not the brightest bulb in the box. please can anyone explain how to do this? I will do anything for help. Does anyone know about this extra row?

i know my rep is worth nothing, but i will repay anyone who helps me with this question!
2. I remember this question, everytime I tried it I got 0 order for B but it was wrong on the mark scheme, move on, I'm pretty sure it's a defective question and you'll get the others right
3. What does the MS say the answers are?
4. Are you sure??? AQA have done this several times with other questions. But what if it isn't a defective question? What if I just can't do it? Imagine if I came across this in an exam...I would have just lost 3 easy marks
5. (Original post by LearningMath)
What does the MS say the answers are?
A is 2
B is 1
C is 0

any ideas on how to do this?
6. (Original post by h-star)
I remember this question, everytime I tried it I got 0 order for B but it was wrong on the mark scheme, move on, I'm pretty sure it's a defective question and you'll get the others right
B isnt zero order.
7. (Original post by Mathematics.)
A is 2
B is 1
C is 0

any ideas on how to do this?
i got A=2
b=1
working on c
8. (Original post by Mathematics.)
A is 2
B is 1
C is 0

any ideas on how to do this?
Excellent same as mine, was slightly apprehensive about giving you wrong answers though. Solid question! I'll just write up my method....
9. (Original post by PsYCho ThInKeR)
i got A=2
b=1
working on c
can you help me?
10. (Original post by LearningMath)
Excellent same as mine, was slightly apprehensive about giving you wrong answers though. Solid question! I'll just write up my method....
you got it so quickly? oh dear. i am dumb then. i'm on the verge of throwing myself off a bridge.
11. (Original post by Mathematics.)
A is 2
B is 1
C is 0

any ideas on how to do this?
lol I actually found these answers without pen/paper. It's not even part of my curriculum (also at A2 level, though).

I'll tell you how I found them, just a sec..!
edit: nvm, someone else (LearningMath) is doing the same. :P

edit: it just struck me that this is a past paper and it's this easy.. A levels must be a cakewalk. no offence meant..
12. (Original post by LearningMath)
B isnt zero order.
Oh well.
13. (Original post by Mathematics.)
can you help me?
for A
look at row 2 and 3.
b goes 0.8 to 0.4. so it halves. the rate should also half making it 0.8. (b has an order of 1)
A doubles.
and the value is 3.2 x 10
3.2 divide by 0.8 = 4
A doubles and rate is times by 4
hence rate is 2. (2:4)
im not very good at explaining. hope u understand
14. (Original post by phen)
lol I actually found these answers without pen/paper. It's not even part of my curriculum (also at A2 level, though).

I'll tell you how I found them, just a sec..!
edit: nvm, someone else (LearningMath) is doing the same. :P

edit: it just struck me that this is a past paper and it's this easy.. A levels must be a cakewalk. no offence meant..
that really didn't help. thanks for ********.
15. First find B since it is the simplist one. Look at rows 1 and 2, concs of A and C are constant and B is doubled twice, the rate also doubles twice. So 1st order.

To find A look at rows 2 and 3, since C is constant and you know the order of B. From row 2 to 3 you are doubling A and halving B. The rate is doubling from 1.6 to 3.2. The only way this could happen was if A was 2nd order, because the rate would quadruple from increase of A(to 6.4x10^-3) and then halve to 3.2x10^-3 as a result of B.

For C, look at rows 3 and 4 since A is constant. The ratio of concentrations of B is exactly the same as the ratios of rates. (0.8/0.3=2.66) and (1.6/0.6=2.6666) which means first order. We know B is first order, so by process of elimination C must be zero order.
16. (Original post by Mathematics.)
that really didn't help. thanks for ********.
I was going to help but you're already being helped, so.. no point in doing so, really.

edit:

I've had your situation at tests (well.. an olympiad) too.. I was completely raped by a complete and utter overdose of material I hadn't at all covered. In the end, I got 36 out of 111 points.. 3 short of making it to the next round. *sigh*
Better luck this year.

Sorry for being a bit inconsiderate.
17. Honestly, I have no idea what its talking about (Being an English student ) but I felt the need to tell you OP that if I had not already used my rep like 2 minutes ago I would have repped you for the title of this thread
18. LearningMath has explained it better.
19. (Original post by PsYCho ThInKeR)
for A
look at row 2 and 3.
b goes 0.8 to 0.4. so it halves. the rate should also half making it 0.8. (b has an order of 1)
A doubles.
and the value is 3.2 x 10
3.2 divide by 0.8 = 4
A doubles and rate is times by 4
hence rate is 2. (2:4)
im not very good at explaining. hope u understand
did you use an extra row? i dont understand.
20. (Original post by LearningMath)
First find B since it is the simplist one. Look at rows 1 and 2, concs of A and C are constant and B is doubled twice, the rate also doubles twice. So 1st order.

To find A look at rows 2 and 3, since C is constant and you know the order of B. From row 2 to 3 you are doubling A and halving B. The rate is doubling from 1.6 to 3.2. The only way this could happen was if A was 2nd order, because the rate would quadruple from increase of A(to 6.4x10^-3) and then halve to 3.2x10^-3 as a result of B.

For C, look at rows 3 and 4 since A is constant. The ratio of concentrations of B is exactly the same as the ratios of rates. (0.8/0.3=2.66) and (1.6/0.6=2.6666) which means first order. We know B is first order, so by process of elimination C must be zero order.
but from row 2 to 3 aren't you halving a and doubling b?

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