March 29, 2024, 01:26:49 AM
Forum Rules: Read This Before Posting


Topic: Determining Percent Acid  (Read 4563 times)

0 Members and 1 Guest are viewing this topic.

Offline Jon Manhattan

  • New Member
  • **
  • Posts: 8
  • Mole Snacks: +0/-0
Determining Percent Acid
« on: March 17, 2009, 01:22:38 PM »
Hi there, I just have a question about calculating the percent acid of an unknown... I took a look at a thread very similar to this, but it didn't fully solve my problem.

If I have a 10.00 mL solution of Acetic Acid - HC2H3O2 - whose molarity I have determined to be 0.195 M with a specific gravity of 1.0980. How do I go about finding the percent acid?

What I know is that % w/w = (mass of substance / mass of solution) x 100.

The mass of the substance would be 11.7 g:

0.195 mol A.A. x (60 g / 1 mol A.A.) = 11.7 g Acetic Acid.

I tried using the specific gravity to find a mass of 10.98:

D = M/V          1.0980 = M / 10.00 mL

but obviously dividing those two would give me a percent greater than 100:

11.7/10.98 x 100

so where did I go wrong here and what should I do? I'm guessing that my determination of the mass of the solution is incorrect... any help would be greatly appreciated!


Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27633
  • Mole Snacks: +1799/-410
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Determining Percent Acid
« Reply #1 on: March 17, 2009, 03:14:41 PM »
0.195M - is 0.195 moles in what volume?
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline Jon Manhattan

  • New Member
  • **
  • Posts: 8
  • Mole Snacks: +0/-0
Re: Determining Percent Acid
« Reply #2 on: March 17, 2009, 03:25:02 PM »
10.00 mL

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27633
  • Mole Snacks: +1799/-410
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Determining Percent Acid
« Reply #3 on: March 17, 2009, 03:48:04 PM »
No. What is definition of molarity?
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline Jon Manhattan

  • New Member
  • **
  • Posts: 8
  • Mole Snacks: +0/-0
Re: Determining Percent Acid
« Reply #4 on: March 17, 2009, 04:07:15 PM »
oh, sorry haha. Molarity is the moles of solute per liter of solution...

Offline Jon Manhattan

  • New Member
  • **
  • Posts: 8
  • Mole Snacks: +0/-0
Re: Determining Percent Acid
« Reply #5 on: March 17, 2009, 04:17:58 PM »
Ohhhhhhhh okay! Wow, what a careless mistake. Thank you very much, no wonder my answer was so far off.. I really appreciate it!

Sponsored Links