To make a long story short, my youngest daughter decided to endure 
through 4 semesters of chemistry, and now is paying up for it. She is 
a talented little girl, but science is not her thing and it hurts for 
me to see her study so hard but understand so little. It runs in the 
family. I wanted to help myself, but me and my wife are no scientists 
at all, plus it was so long ago. Tutoring is very very weak at where 
she goes, and we know few friends around here who are capable of 
helping, most of which already are looking at us the wrong way for 
asking so much. I decided to open my pocket and let you, Chemistry 
folks, help us out. I secretly took the next set of questions from my 
daughters assignment section, and here they are. I understand that 
many (or most) of you would have the problem to giving direct help 
like this, "learning and understanding the material is the most 
important", right ? Wrong. Only but a few of you would understand the 
pain I feel when I see my daughter quietly cry in her room over her 
low assignment grades after hours and hours of studying daily. 
  
Below I copied down some of the questions and choice answers that came 
along. I tried my best to copy down everything number to number, word 
for word. Its a little bit difficult to transfer everything to text, 
but I tried. Please feel free to clarify if you did not understand a 
part. 
  
I am asking for a list of answers to the problems, in numerical + 
content format, as such : 
  
Question 1: Answer 3. The number of moles is 4.0.  
Question 2: Answer 5. The reaction is reversed.  
  
Time is an issue, but I would like the answers to be correct. I do not 
want to check my daughters answers and tell her that one of her 
correct answers is incorrect simply because what was given to me is a 
wrong answer. Once again I apologize for such rude question, but I am 
desperate, and I ran out of all other options. I am also considering a 
big tip for those who'll work hard on these, do all (or most) of the 
questions, provide the correct answers and hopefully as soon as 
possible. 
  
Thank you once more. You are my last hope. 

1) Oxalic acid is a diprotic acid with k1 = 5.9 * 10^-2
and k2 = 6.4 * 10^-5. A dilute solution of
potassium hydrogen oxalate would be

1. acidic because hydrolysis of the anion
would predominate over further dissociation
2. basic because further dissociation of the
3. basic because hydrolysis of the anion
would predominate over further dissociation
anion would predominate over hydrolysis
4. acidic because further dissociation of the
anion would predominate over hydrolysis
5. neutral

2) Ka for HClO is 3.5 * 10^-8 . What is the
pH of a 0.3 M solution of HClO? You may
approximate the full quadratic for problem
because Kc is so small. 
The reaction is: HClO + H2O --> H3O+ + ClO-
(Kw = 1 * 10^-14).

1. 10.0
2. 3.7
3. 5.2
4. 4.0
5. 7.5


3) What is the concentration of H3O+ ions in
a 0.10 M solution of Ba(OH)2, a strong elec-
trolyte, at 25deg Celcius ?

1. none
2. 1.0 * 10^-1 M
3. 1.0 * 10^-13 M
4. 2.5 * 10^-13 M
5. 5.0 * 10^-14 M


4) Like all equilibrium constants, Kw varies
somewhat with temperature.

Given that Kw is 7.6 * 10^-13 at some temperature, 
compute the pH of a neutral aqueous solution at that 
temperature. Answer in units of pH.

<Numerical Answer>

5) Which of the following substances is NOT a
strong electrolyte?

1. HClO4
2. NH4Cl
3. NH3
4. Mg(NO3)2
5. HNO3

Hello again, Jwheel.

I see this is the last set of your questions to get answered.  I hope
that all the solutions have helped you.

The answers:

Question 1: Answer: 4, assuming that "the anion" referred to in the
question mean HOx- and not Ox^2-.

Question 2: Answer: 2

HClO      <->    H+    +    OCl-
0.3M             0           0      (start)
 - x             +x         +x      (change)
0.3 - x          +x         +x      (equilibrium)

Ka = 3.5*10^-8 
= x^2 / (0.3 - x) 
=~ x^2 / 0.3

x = Sqrt( 3.5*10^-8 * 0.3)
x = 0.00010247
pH = -Log10 x
pH = 3.989, or very close to 4.0

Question 3: Answer 5

If c(BaOH2) = 0.10M
[OH-] = 0.20M
[H+] = 1.0*10^-14 / 0.2 
     = 5*10^-14

Question 4: Answer:

Kw = [H+][OH-]
In pure water [H+] = [OH-]
So 7.6*10^-13 = x * x = x^2
x = Sqrt( 7.6*10^-13 )
x = 8.7178*10^-7
pH = -Log10 x
pH = 6.05959

Question 5: Answer: 3, all others are strong electrolytes.

------------

Best of luck to your daughter.  If you have any questions, please let
me know.

Hibiscus

I just signed up right now to give a comment here.  Hopefully it's not
against Google policy.  It should be considering my comment :)

It is apparent that you love your daughter very much.  You want to see
her get good grades but this isn't right.  You are spending some
ridiculous amount of money for some simple Introductory Chemistry
problems.  (I took that course last year :))  If you just want the
answers, why not buy the solution guide?  Most of the questions you
posted are "redundant" anyway - same concept.  I am sure the amount of
money you are willing to spend, You should be able to get a good tutor
even if you believe there are none around your area.  I think someone
recommended you to contact the local university in one of your posts
(Good idea).  Anyways, it's your problem and you will do whatever you
feel best.  But I did feel the urgency to comment from your touchy
anecdote... Peace and good luck!

Another thing is She can also get help from her classmates.  I am sure
somebody in her class understands this crappy subject!

jwheel-ga,

I must say that I concur with the sentiments of imtiaz03-ga's Comment.
I also took college several college chemistry courses, and I know
firsthand how dikfficult this material can become, but simply having
the answers to the problem sets will not make one understand how to do
them.

For the same asking price of your current problem sets, you could ask
a different question on Google Answers that focused more on finding
chemistry tutors and chemistry learning resources in your area,
perhaps even your daughter's specific school. Also, you ask those who
have succeeded in chemsitry courses to outline in detail their study
strategies. This would be much more valuable to her in the long run
than having the answers to one problem set, even if those answers are
accompanied by some explanation.

omniscientbeing-ga
Google Answers Researcher

I agree with the others, buying answers was probably not the best
thing to do, since the money only bought you how to do these specific
problems, not any others.