calculate moles in excel

  • Thread starter Thread starter Dave
  • Start date Start date
D

Dave

HELP!

How in Excel do I work out how many moles are in 1kg of water. Desperately
need an answer for Monday morning.

:)
 
Hi,

So it's homework time is it?

Firstly you can't do it solely in Excel without reference to a table of
atomic weights and from that you should discover the following:-

Hydrogen atomic weight = 1.0079
Oxygen atomic weight = 15.994
Put these 2 values in A1(hydrogen) and A2(oxygen)
Now work out number of moles with this formula
=1000/(A1*2+A2)

To make it more flexible you could put the 1000gms in a cell and reference
it in the formula
=A3/(A1*2+A2)


Mike
 
OK I understand that but my Chem tutor keeps rattling on about avagardos
constant and I thought i need that to work out moles
 
Hi,

It's actually Avagadro's constant and you don't need to know that to work
out moles but it would be well to understand it.

I'm aware we are stepping over the boundary here from excel to chemistry and
I'm no expert in either but here we go.

Avagadro's constant is a number that is the amount of units of a thing that
are in 1 mole of that thing and I use 'thing' because there is no standard
unit for it.

The constant is actually 6.022 *10^23 (which is a very big number). So 1
mole of computers is 6.022 * 10^23 computers, 1 mole of Excel MVP's is 6.022
* 10^23 MVP's and for 1 mole of water we do the same sum.

So to get back to your question 1000gms of water is roughly 55.52 moles so
multiply that by Avagadro's constant and that's how many molecules of H2O are
in 1000gms of water.


Mike
 
The proper spelling is Avagadro's Constant and can be found by searching
the 'net.

I sincerely hope your instructor did not teach you "avagardos constant"


Gord Dibben MS Excel MVP
 
Considering the quality of the ability, or lack thereof, of today's college
graduates to even formulate a proper sentence, I think chances are probably
about 50/50 that he was taught avagardos constant instead of Avagadro's
Constant.

Can't put all the blame on the student when the faculty and administrators
keep lowering standards to make sure no child suffers the terrible,
life-long-lasting stigma of actually being held back a year until they learn
what everyone else did.
 
Unfortunately, I think you may be right Jerry

I am positive that not all the posters with the spelling and grammatical
mistakes are high school or grade school drop-outs.


Gord
 
The proper spelling is Avagadro's Constant and can be found by searching
the 'net.

I sincerely hope your instructor did not teach you "avagardos constant"

Gord Dibben MS Excel MVP
Click to expand...

But it's Avogadro.

Ken Johnson
 
Damn! Good thing I didn't choose kimystery as a major! Thanks for the
correction to the correction, seriously.

How odd that I should have forgotten how to spell it after only about 40
years of never so much as using it in a sentence or uttering it in
conversation.
 
Hi,

Now that's interesting, both yourself and GD discuss high/grade school which
I guess are US terms and then comment on standards making the assumption; I
think, that this guy is from the US. Me, I'm convinced he's English, the
problem is pandemic.

Mike
 
Ken,

Interesting point. There are probably as many references to Avagadro as
Avogadro on the net and in textbooks but what we can agree on completely is
that it isn't avagardo and a man of such eminence; at the very least,
deserves his name to be spelt with a capital A.

Mike
 
Thank goodness he got an answer earlier, because we've certainly not only
hijacked his thread, but thoroughly derailed it!

I haven't been abroad for some years now, so I wasn't aware that this was
becoming, or has become, such a widespread condition. I just thought that
store clerks who cannot calculate change on a sale in their head, engineers
who stare blankly at a sliderule, and people who are so clueless to the
geography of their own area that they don't know which side of the largest
river in their country they live on was an American disaster. I must get out
more.
 
Ken,

Interesting point. There are probably as many references to Avagadro as
Avogadro on the net and in textbooks but what we can agree on completely is
that it isn't avagardo and a man of such eminence; at the very least,
deserves his name to be spelt with a capital A.

Mike
Click to expand...

Mike,

Very interesting. I had no idea so many people have been getting it
wrong.

Ken Johnson
 
"I started it...." --- G.D.

Let's just take the root of all this evil out back and simply shoot him! :)
 
Mike wrote on Sun, 11 May 2008 01:16:00 -0700:
Interesting point. There are probably as many references to
Avagadro as Avogadro on the net and in textbooks but what we
can agree on completely is that it isn't avagardo and a man of
such eminence; at the very least, deserves his name to be
spelt with a capital A.
Click to expand...
Mike
Click to expand...

Well, the Google count is 454 000 for Avogadro and 38 000 for
Avagadro. So, if a good number do get it wrong, most don't
(92%). I wonder if a number of us ancients are confused by a
long-standing admiration for the actress Ava Gardner? :-)

Just to confuse things, an actual value of Avogadro's number was
first calculated by J.J. Loschmidt and some people, especially
in Germany, distinguish between "Avogadro's Hypothesis" and the
"Loschmidt Number".
--

James Silverton
Potomac, Maryland

E-mail, with obvious alterations:
not.jim.silverton.at.verizon.not
 
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