January 25, 2021, 02:01:27 PM
Forum Rules: Read This Before Posting


Topic: Chemistry Exam Review  (Read 5899 times)

0 Members and 1 Guest are viewing this topic.

Offline sallyhansen

  • Regular Member
  • ***
  • Posts: 63
  • Mole Snacks: +1/-0
Re: Chemistry Exam Review
« Reply #15 on: May 11, 2013, 09:33:49 PM »
Can you show us what you did for 5? Did you manage to set up the general rate law equation? Do you know what n and m represent?
Regarding question 7, you need to put in the equilibrium concentrations when solving for K, i.e. K = x/([0.225-x][0.150-x])
I do believe there is a typo in question 11 as the answer has Pb2+ while the question has Pb2+ so either the question is wrong or the answer is wrong, I reckon it is the question. There is nothing much you can do about that, perhaps try the balance again with Pb2+ and see if you get the right answer

For number 5 I actually don't know what n and m represent

Offline iamback

  • Regular Member
  • ***
  • Posts: 34
  • Mole Snacks: +2/-2
Re: Chemistry Exam Review
« Reply #16 on: May 11, 2013, 11:56:31 PM »
^^Do you remember the general rate law ?

Rate = k[X]m[y]n

where is k is rate constant.

Here n is the coefficient of [OH], and m is coefficient of [ClO2] in rate law.

Can you now solve it on your own ?

Offline sallyhansen

  • Regular Member
  • ***
  • Posts: 63
  • Mole Snacks: +1/-0
Re: Chemistry Exam Review
« Reply #17 on: May 12, 2013, 03:13:23 PM »
^^Do you remember the general rate law ?

Rate = k[X]m[y]n

where is k is rate constant.

Here n is the coefficient of [OH], and m is coefficient of [ClO2] in rate law.

Can you now solve it on your own ?

For a question like this how would I calculate for X
1.6 × 10-48 = 4× 3

The answer is × = 7.4 × 10-17 mol/L but how do I get rid of an exponent with a 3É

Offline iamback

  • Regular Member
  • ***
  • Posts: 34
  • Mole Snacks: +2/-2
Re: Chemistry Exam Review
« Reply #18 on: May 12, 2013, 10:18:47 PM »
You don't have calculate of for X. You are given the values of X and Y here in the question.

X and Y are the concentrations of [ClO2] and [OH] respectively.

Form equations with the data given and solve.

I am forming one for you.

Rate = k[X]m[Y]n

0.18 = k[0.10]m[0.10]n

Now make equations like this and solve for m, n and k.

Offline sallyhansen

  • Regular Member
  • ***
  • Posts: 63
  • Mole Snacks: +1/-0
Re: Chemistry Exam Review
« Reply #19 on: May 13, 2013, 03:02:06 PM »
You don't have calculate of for X. You are given the values of X and Y here in the question.

X and Y are the concentrations of [ClO2] and [OH] respectively.

Form equations with the data given and solve.

I am forming one for you.

Rate = k[X]m[Y]n

0.18 = k[0.10]m[0.10]n

Now make equations like this and solve for m, n and k.

No the above question was a different question entirely

Offline iamback

  • Regular Member
  • ***
  • Posts: 34
  • Mole Snacks: +2/-2
Re: Chemistry Exam Review
« Reply #20 on: May 14, 2013, 12:16:33 AM »
I solved it, and got the right answer, which you have mentioned in red letters.

Sponsored Links