October 25, 2021, 05:01:37 PM
Forum Rules: Read This Before Posting


Topic: Another Ksp Related Question  (Read 3307 times)

0 Members and 1 Guest are viewing this topic.

dagr8est

  • Guest
Another Ksp Related Question
« on: April 09, 2006, 02:19:19 PM »
Sigh, I am starting to think that every answer on this answer key is wrong...  If someone can confirm that I did this question correctly, I will just disregard the answer key for the rest of the questions.

***

Calculate the Ag+ concentration required to start a precipitation of AgBrO3 from a solution containing 0.50g of NaBrO3 per 0.300 litre.  Ksp of AgBrO3 = 5.3(10-5)

***

[BrO3-] = [NaBrO3] = 0.50g(1mol/127.9g)(1/0.300L) = 0.013M

Ksp = [Ag+][BrO3-]
5.3(10-5) = [Ag+](0.013M)
4.1(10-3)M = [Ag+]

Answer key says it's 4.5(10-11)M...
« Last Edit: April 09, 2006, 02:20:51 PM by dagr8est »

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 26802
  • Mole Snacks: +1737/-403
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Another Ksp Related Question
« Reply #1 on: April 09, 2006, 02:52:45 PM »
Seems to me it should be 4.8*10-3, so both answers are wrong. Check molar mass of sodium bromate.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info, pH-meter.info

dagr8est

  • Guest
Re: Another Ksp Related Question
« Reply #2 on: April 09, 2006, 03:15:42 PM »
Oh yeah whoops, I forgot to include sodium.  I agree it should be 4.8(10^-3)M then.  I guess this answer key is just completely wrong then.  Thanks for the help on both questions. ;D

Offline AWK

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7982
  • Mole Snacks: +555/-93
  • Gender: Male
Re: Another Ksp Related Question
« Reply #3 on: April 10, 2006, 12:15:47 AM »
MM  of NaBrO3 is ~ 151
AWK

Sponsored Links