May 31, 2020, 03:17:44 AM
Forum Rules: Read This Before Posting


Topic: calculating pH and hydronium ion concentration.  (Read 11454 times)

0 Members and 1 Guest are viewing this topic.

Offline 2clients

  • Regular Member
  • ***
  • Posts: 13
  • Mole Snacks: +0/-1
calculating pH and hydronium ion concentration.
« on: March 17, 2009, 05:21:48 PM »
Hello there,

I'm a little lost on this one:

Calculate the hydronium ion concentration and pH in a 0.5 M solution of NH4Cl.

I know pH = -log[H+], but I'm unsure how to find [H+].  Probably I need a Ka value for NH4Cl?

Any help is greatly appreciated!

David

Offline 2clients

  • Regular Member
  • ***
  • Posts: 13
  • Mole Snacks: +0/-1
Re: calculating pH and hydronium ion concentration.
« Reply #1 on: March 17, 2009, 05:29:44 PM »
So after thinking about it more, I think an ICE table is appropriate here, and I could set (x^2)/(.5-x) = Ka of NH4Cl.

Solving for x will give [H+] and then I could take the negative log to get pH? I'm not finding the Ka value online...

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 25773
  • Mole Snacks: +1686/-400
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: calculating pH and hydronium ion concentration.
« Reply #2 on: March 17, 2009, 06:13:40 PM »
NH4+ is a conjugate acid of a weak base.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info, pH-meter.info

Sponsored Links