December 22, 2024, 11:00:03 AM
Forum Rules: Read This Before Posting


Topic: please let me know if this is correct  (Read 6336 times)

0 Members and 1 Guest are viewing this topic.

Offline bio

  • New Member
  • **
  • Posts: 5
  • Mole Snacks: +0/-0
please let me know if this is correct
« on: April 29, 2007, 08:10:25 AM »
I calculated this problem but I don't think it's right, please let me know!!!!!!!!


Determine Ph of a 0.15 m solution of KF (ka=7.0x10-4)

my calculations: 7.0x10-4/0.15 = 4.66x10-3

 Log of 4.66x10-3= 2.33

 It doen't seem to me that it's correct but I wanna check if I set it up correctly!

 Thanks in advance!!

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27885
  • Mole Snacks: +1815/-412
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: please let me know if this is correct
« Reply #1 on: April 29, 2007, 08:56:21 AM »
It can't be acidic - F- is a weak base, so the solution must have pH above 7.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline Yggdrasil

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 3215
  • Mole Snacks: +485/-21
  • Gender: Male
  • Physical Biochemist
Re: please let me know if this is correct
« Reply #2 on: April 29, 2007, 02:35:19 PM »
You need to set up an ICE table to figure out the pH of the solution.  But, first, what is the chemical reaction that happens when you dissolve KF in water?

Sponsored Links