Hi there, I was wondering if anyone could help me with 3 questions:
1) Without pH papers, how do you calculate the pH of a 5% H2SO4 (sulfuric acid) solution?
I know vinegar is a weak acid, but would a 5% acetic acid have the same pH of a %5 H2So4 solution?

2) If a non-polar solvent such as Hexane is miscible with Ethanol, does that mean that they mix completely? If so, would the water traces from the alcohol stay at the bottom below the Hexane layer?

3) H202 (Hydrogen peroxide) is an oxidizing agent just like Permanganate. I need to replace the later, is it possible to dilute or concentrate Peroxide in order to make it work like Permanganate?
Besides one begin stronger than the other, what other differences are there between these oxidizing agents? 

Thanks 

http://www.chembuddy.com/?left=pH-calculation&right=toc

1) Without pH papers, how do you calculate the pH of a 5% H2SO4 (sulfuric acid) solution?

Convert to molarity first, then follow information from the multiprotic acid pH lecture. But I am afraid it will be way over your head, as the question you asked suggests you know next to nothing about acids and pH.

I know vinegar is a weak acid, but would a 5% acetic acid have the same pH of a %5 H2So4 solution?

First, pH is based on molarity, so 5% solutions of acetic acid and sulfuric acid are completely different.

Second, pH depends on whether the acid is strong or weak, so acetic acid solution and sulfuric acid solution are completely different.

Third, pH depends on number of protons that can dissociate, so acetic acid solution and sulfuric acid solution are completely different.

I can't give you a simple answer for number 2, I'm not sure.  A trace of water my drop out, or may forma a stable emulsion, like grease in water with detergent.

I don't want to give you the answer to number 3.  It seems a dangerous thing to do if you're not sure of what you're doing.  And since you're obsessed with knowing "just enough" and no more than that -- you likely don't know what you're doing.

With some work on your part, you can use the webpage posted to help you understand the underlying concepts for number 1.  Then, you'll be able to figure out 3%, 7% whatever concentration of whatever acid you encounter.  That saves us the trouble of explaining each situation to you each time -- yes, even if you're not doing schoolwork, we don't want to teach you a months worth of chemistry, one posting at a time.

Pleasure to work with you, $@#&%$&$#