October 25, 2021, 04:07:20 AM
Forum Rules: Read This Before Posting


Topic: Carbonic Acid and Salts Lab  (Read 31929 times)

0 Members and 1 Guest are viewing this topic.

MilchstrabeStern

  • Guest
Re:Carbonic Acid and Salts Lab
« Reply #45 on: September 07, 2005, 02:30:20 PM »
But anyways guys, now that we know that we are dealing with SELTZER water (carbonic acid) and not alka seltzer water, I think we can finish this.

I understand how the CaCl2 decreases the amount of CO2 gas produced. I'm still unsure about how the NaCl affects it. Is it really just decreasing the interaction of the H2CO3 and the H2O?

MilchstrabeStern

  • Guest
Re:Carbonic Acid and Salts Lab
« Reply #46 on: September 08, 2005, 01:38:25 AM »
Hey you know what! Check this out:

H2CO3 is a stable compound alone.

However when it interacts with water it readily decomposes into H2O and CO2.

Now the reason this occurs i'm not 100% sure but I thought it may have to do with the polarity of water and the fact that water is a product of the decomposition.

When you throw NaCL in and get the Na + and Cl- ions, don't they stick to the water molecules based on the fact that water is polar? Thus t his decreases the amount of water molecules that can interact with the H2CO3? As a result the decomposition decreases?

What do you guys think?

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 26801
  • Mole Snacks: +1737/-403
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re:Carbonic Acid and Salts Lab
« Reply #47 on: September 08, 2005, 03:47:17 AM »
When you throw NaCL in and get the Na + and Cl- ions, don't they stick to the water molecules based on the fact that water is polar? Thus t his decreases the amount of water molecules that can interact with the H2CO3? As a result the decomposition decreases?

Traces of water are enough for carbonic acid decomposition. Concentration of water in pure water is 55.51M. In the CaCl2/NaCl solutions concentration of water is lowered to - say - 55.43M. That's 0.14% difference. It is very doubtfull to me that's what changes speed of CO2 evolution in measurable degree (taking into account accuracy of the experiment on the whole).
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info, pH-meter.info

Sponsored Links