December 24, 2024, 07:24:58 AM
Forum Rules: Read This Before Posting


« previous next »
Pages: [1]   Go Down

Topic: amount (in kg) to be dissolved in a saturated solution?  (Read 2978 times)

0 Members and 2 Guests are viewing this topic.

Offline ichidp

  • Regular Member
  • ***
  • Posts: 10
  • Mole Snacks: +0/-1
amount (in kg) to be dissolved in a saturated solution?
« on: September 08, 2012, 02:59:44 AM »
the problem is:

How much CaCl2 6H2O must dissolved in 100 kg of water at 20° C to form a saturated solution? The solubility of CaCl2 at 20° C is 6.7 gmol anhydrous salt (CaCl2) per 100 kg water.

what i did was took the kg of CaCl2 6H20 from the (MW CaCl2 6H20)/(MW CaCl2) ratio multiplied by 100kg water multiplied by the given solubility which i converted to (kg CaCl2/kg water).

the answer i got was 148.598 kg CaCl2 6H2O. however, the answer according to the answer key was 535 kg. i don't understand why. any help is very much appreciated, thank you! :)
Logged

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27888
  • Mole Snacks: +1816/-412
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: amount (in kg) to be dissolved in a saturated solution?
« Reply #1 on: September 08, 2012, 03:29:33 AM »
Seems to me like you forgot you are changing amount of solvent.
Logged
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline ichidp

  • Regular Member
  • ***
  • Posts: 10
  • Mole Snacks: +0/-1
Re: amount (in kg) to be dissolved in a saturated solution?
« Reply #2 on: September 08, 2012, 03:37:14 AM »
solvent? i thought, the solvent was given as 100kg, so why would it change?
Logged

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27888
  • Mole Snacks: +1816/-412
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: amount (in kg) to be dissolved in a saturated solution?
« Reply #3 on: September 08, 2012, 03:42:09 AM »
CaCl2·6H2O
Logged
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline ichidp

  • Regular Member
  • ***
  • Posts: 10
  • Mole Snacks: +0/-1
Re: amount (in kg) to be dissolved in a saturated solution?
« Reply #4 on: September 08, 2012, 04:26:51 AM »
wow. i think i finally got it, well, close to 535, i got 531 kg.. thanks!

i actually gave the wrong given up there, the solubility is supposed to be  6.7 gmol anhydrous salt (CaCl2) per kg water.
Logged
Pages: [1]   Go Up
« previous next »
Sponsored Links