Gchem rate question

[_veo_]

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For the reaction: A + B → C, determine the order of the
reaction with respect to B from the information given
below.

Initial [A] Initial Initial rate of formation of C (mol/L•min)
2.5 x 10–6 3 x 10-4 5 x 10–3
5 x 10–6 3 x 10-4 1 x 10–2
1 x 10–5 9 x 10-4 1.8 x 10–1


A. zero order
B. first order
C. second order
D. third order
E. fourth order

These kind of questions are usually easy, but this one is confusing me. I get that A would be first order, but I don't know how to get B. Any help please?

 

[GRAD]

Try to simplify it - i think thats the easiest way..

A

1
2
4

B
1
1
3

Rate
1
2
36

ok so now that its simplified, you know that in 1 and 2, B doesnt change and the rate is the exact same as A, so when you have 2, the rate is also 2...

Ok then you look at # 3, where you have 4 of A, and 3 of B, and get 36. From the other two trials, you know that A is going to stay the same, so its gonna be [A]1, and so you just divide 36 by 4, and you get 9, and that means its 3 squared! So you know its K[A]12!!

I was really confused on these ones cause i tried to do it by the equation, its way easier to simplify. Hopefully i didnt confuse you...

 

[_veo_]

Try to simplify it - i think thats the easiest way..

A

1
2
4

B
1
1
3

Rate
1
2
36

ok so now that its simplified, you know that in 1 and 2, B doesnt change and the rate is the exact same as A, so when you have 2, the rate is also 2...

Ok then you look at # 3, where you have 4 of A, and 3 of B, and get 36. From the other two trials, you know that A is going to stay the same, so its gonna be [A]1, and so you just divide 36 by 4, and you get 9, and that means its 3 squared! So you know its K[A]12!!

I was really confused on these ones cause i tried to do it by the equation, its way easier to simplify. Hopefully i didnt confuse you...

Thank you very much. Simplifying makes it way easier!

I can't understand this other question. Gchem is definitely my weakness 🙁

A 200 mL flask contains oxygen at 200 mmHg, and a 300
mL flask contains neon at 100 mmHg. The two flasks are
then connected so that each gas fills their combined
volumes. Assuming no change in temperature, what is the
partial pressure of neon in the final mixture?
A. 60 mmHg
B. 80 mmHg
C. 100 mmHg
D. 150 mmHg
E 200 mmHg

The answer is A

 

[GRAD]

yeah these are from the Kaplan Subject tests huh..

I believe with those you multiply the pressure of the one you want by the volume of the one you want divided by the total...
I was confusd by these too....i guess just memorize the formula

100*300/500

 

[_veo_]

yeah these are from the Kaplan Subject tests huh..

I believe with those you multiply the pressure of the one you want by the volume of the one you want divided by the total...
I was confusd by these too....i guess just memorize the formula

100*300/500

Thank you very much
Yes, these are from the kaplan subject tests. I'm freaking out because I got about half correct 😕