Re: plz someone help with this problem relating to chemical reaction

On May 31, 12:23 am, Bob <bbx107....@xxxxxxxxxxxxxx> wrote:
On Wed, 30 May 2007 09:18:47 +0200, Borek

<m.borkow...@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
On Wed, 30 May 2007 06:58:21 +0200, Bob <bbx107....@xxxxxxxxxxxxxx> wrote:

OK, my bad, it's at 25 C.

and has water vapor in it

My take is that partial pressure of water is to be ignored. Seems like
basic pV=nRT question.

It's more than that. It is a "collection of gas over water" problem.


Well, going back to the original question...

The h2 is
collected over water at a temperature of 25c and a total pressure of
762 mmhg.

If it says "collected over water" and "total pressure", I'd take the
water pressure into account.

No. Once the water level reaches equilibrium during the experiment, it
means that the total pressure inside the collection vessel equalls the
atmospheric pressure. The atmospheric pressure is read using a
barometer. The pressure inside the vesel consists of two terms - the
partial pressure of the H2, and the partial pressure of the water
vapor.

The partial pressure of water vapor is well-tabulated (just look it up
in a table, based on the temperature). This procedure doesn't work for
gases which either recat with the water or dissolve in it.

But who knows. The OP has vaporized.

bob


.

Relevant Pages

  • Homebrew Digest #5359 (July 01, 2008)
    ... FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES ... THIS YEAR'S HOME BREW DIGEST BROUGHT TO YOU BY: ... Re: Water Chemistry ... Yeast Performance Versus Pressure ...
    (rec.crafts.brewing)
  • Re: Why are very large trees tall?
    ... to transport water. ... Get a glass of water and a straw. ... your experiment does not involve negative pressure unless the ... very fine hydrophobic lines, surrounding hydrophilic cells. ...
    (talk.origins)
  • Re: EL NINO OR LA NINA causes which type of weather?
    ... What it is is the pressure differences between Low pressure areas and ... statistical evidence for widespread climatic anomalies around the ... the westward trade winds typically blow more intensely along ... the equator in the equatorial Pacific, causing warm upper-ocean water ...
    (sci.geo.meteorology)
  • Re: Why are very large trees tall?
    ... to transport water. ... Get a glass of water and a straw. ... your experiment does not involve negative pressure unless the ... very fine hydrophobic lines, surrounding hydrophilic cells. ...
    (talk.origins)
  • Re: Dense fogs in Valles Marineris Mars.
    ... > appears to be a pool of liquid water showing at the far right of the ... pressure at 10 deg C is 9.209 mmHg. ... Since water can only exist in liquid ... level and its average temperature. ...
    (sci.geo.meteorology)