December 23, 2024, 03:53:13 AM
Forum Rules: Read This Before Posting


Topic: Molality Question  (Read 3819 times)

0 Members and 1 Guest are viewing this topic.

Offline rgoad22

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Molality Question
« on: February 04, 2013, 08:39:11 PM »
I'm having trouble with solving this problem. Any suggestions?

Find the concentration of H2SO4 solution in mol/kg if a 10.063 g aliquot of H2SO4 solution required 57.911 grams of NaOH solution to reach the phenolphthalein endpoint.

I tried doing a molar ratio of H2SO4 and NaOH and then doing the necessary conversions but I can't get the right answer.

Offline Arkcon

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7367
  • Mole Snacks: +533/-147
Re: Molality Question
« Reply #1 on: February 04, 2013, 10:05:04 PM »
You will need the concentration of the NaOH solution to be known.  Once you try it, what answer do you get?
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline rgoad22

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Re: Molality Question
« Reply #2 on: February 04, 2013, 10:17:45 PM »
I have 0.006098 moles of NaOH. So then I divided by 2 for the molar ratio, multplied by the molecular weight of H2SO4, and divided by the given kg of H2SO4 that were used. I got .00301 but the answer should be 0.286 mol/kg :/

Sponsored Links