November 25, 2024, 08:56:23 PM
Forum Rules: Read This Before Posting


Topic: how does the pH change? (Half difficult, half easy problem)  (Read 1443 times)

0 Members and 1 Guest are viewing this topic.

Offline Optikspik

  • Very New Member
  • *
  • Posts: 1
  • Mole Snacks: +0/-0
how does the pH change? (Half difficult, half easy problem)
« on: October 21, 2015, 12:50:27 PM »
If U have 0,3 Molar of carbonic acid and the [CO_32- is 2*10-13M in a system of the following equlibriums:
H2CO3 <=> H+ HCo3(-)
HCO3(-) <=> H+ CO3(2-) How will the pH vaulebe affected if u add LiHCO_3 to the reaction?
Given is that kb for HCO3(-) is bigger than ka so it works more like a base than an acid. But Im unsure how i use le chateliers principle to answer this question? How should i resonate?
Thanks in advance :)

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27864
  • Mole Snacks: +1813/-412
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: how does the pH change? (Half difficult, half easy problem)
« Reply #1 on: October 21, 2015, 03:06:26 PM »
Concentration of CO32- doesn't matter. If you have a solution of carbonic acid its pH is dominated by the first dissociation step. What happens to the first dissociation equilibrium when you add HCO3-?
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Sponsored Links