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Topic: Gas density with Temp  (Read 5313 times)

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submar1ney

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Gas density with Temp
« on: January 17, 2008, 10:11:55 AM »
I've just worked out using Charles' Law that when a gas (ammonia) is prepared at a temperature of 25 Deg C (298K), the volume of 1 litre increases to approx 1.091 litres. I've also calculated the density decreases from 0.760g/l to 0.696g/l. Do this sound correct? The pressure remains constant. And the gas, i'm led to believe isn't in a sealed container.

Thank you

Offline Borek

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Re: Gas density with Temp
« Reply #1 on: January 17, 2008, 10:19:52 AM »
I've just worked out using Charles' Law that when a gas (ammonia) is prepared at a temperature of 25 Deg C (298K), the volume of 1 litre increases to approx 1.091 litres. I've also calculated the density decreases from 0.760g/l to 0.696g/l. Do this sound correct?

It sounds incorrect - 1L is always 1L. Please elaborate what you mean by "when prepared volume increases". I suppose you have posted omitting part of the information given in the question,
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submar1ney

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Re: Gas density with Temp
« Reply #2 on: January 17, 2008, 10:25:20 AM »
I've just worked out using Charles' Law that when a gas (ammonia) is prepared at a temperature of 25 Deg C (298K), the volume of 1 litre increases to approx 1.091 litres. I've also calculated the density decreases from 0.760g/l to 0.696g/l. Do this sound correct?

It sounds incorrect - 1L is always 1L. Please elaborate what you mean by "when prepared volume increases". I suppose you have posted omitting part of the information given in the question,

Of course...

the question states, determine the volume that 1 liter at STP would have, at 25 deg C and 760mmHg

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Re: Gas density with Temp
« Reply #3 on: January 17, 2008, 10:56:34 AM »
Depends on what you (or rather your prof) means by STP...

http://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressure
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submar1ney

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Re: Gas density with Temp
« Reply #4 on: January 17, 2008, 12:01:44 PM »
Depends on what you (or rather your prof) means by STP...

http://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressure

In this case, STP is 0 deg C and 260mmHg

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Re: Gas density with Temp
« Reply #5 on: January 17, 2008, 12:24:00 PM »
In this case, STP is 0 deg C and 260mmHg

You sure about 260?  :D

But assuming 760 - your results are OK.
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submar1ney

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Re: Gas density with Temp
« Reply #6 on: January 17, 2008, 12:39:50 PM »
In this case, STP is 0 deg C and 260mmHg

You sure about 260?  :D

But assuming 760 - your results are OK.


OOOOPS, yes. 760mmHg. Time to take a break i think lol...   Many thanks for your help and re-assurance


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