May 06, 2021, 12:40:02 PM
Forum Rules: Read This Before Posting

### Topic: H2SO4 Help me!  (Read 9932 times)

0 Members and 1 Guest are viewing this topic.

#### Borek

• Mr. pH
• Deity Member
• Posts: 26485
• Mole Snacks: +1721/-402
• Gender:
• I am known to be occasionally wrong.
##### Re: H2SO4 Help me!
« Reply #15 on: March 24, 2008, 05:39:14 PM »
No idea what you mean.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info, pH-meter.info

#### Saint

• Regular Member
• Posts: 11
• Mole Snacks: +0/-1
• Gender:
• When I study Chemistry, I get serious...
##### Re: H2SO4 Help me!
« Reply #16 on: March 24, 2008, 06:25:34 PM »
I didn't finished my reply my internet was cut.
Now...
That typo you gave to me the Hederson one exists only when the approximations work.
Here after ionizations and with C H2SO4's concentration we have:
1) C+x=10-4 (from the ph)
2) 10-2=x*10-4/C-x  (from the second ionization)
Well that Hederson typo is the 2) but with the approximations:
3) 10-2=x*10-4/C

If we solve 1-3 we find that C=x which is impossible
If we solve the 1-2 we take "reasonable" results which I'll write down tomorrow...
I hope you understand... Goodnight...
E=mc2

#### AWK

• Retired Staff
• Sr. Member
• Posts: 7984
• Mole Snacks: +555/-93
• Gender:
##### Re: H2SO4 Help me!
« Reply #17 on: March 25, 2008, 03:20:25 AM »
H2SO4 with pH 4 and NaOH with pH 10 practically forms Na2SO4 with concentration 2.5 10-5 M (error less then 0.5 %). I think this problem can be approximately treated as hydrolysis of Na2SO4 instead of buffer Na2SO4/NaHSO4 far outside of reasonable bufferring capacity range.

I think Borek can check both possibilities with his program
AWK