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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: jesss on October 21, 2014, 02:26:32 PM

Title: Calculating the concentration of a gas knowing the volume and temperature
Post by: jesss on October 21, 2014, 02:26:32 PM

Hi,

I would really appreciate some help with the following question, I am sure there is a relatively simple answer but I am hitting a brick wall at the moment.

A container is filled with nitric oxide (NO) to a pressure of 10 bar at 300 K. What is the concentration of the nitric oxide in moles m-3 ?
What would be the concentration of cyanogen (C2N2) at the same temperature and pressure? Which principle does this demonstrate?

I have gone through all the gas laws that we have been studying during lectures but i cannot find one that fits for this question.

Thank you!

Title: Re: Calculating the concentration of a gas knowing the volume and temperature
Post by: Borek on October 21, 2014, 02:58:54 PM

Concentration is moles per liter, isn't it?

Title: Re: Calculating the concentration of a gas knowing the volume and temperature
Post by: jesss on October 21, 2014, 03:17:02 PM

Quote from: Borek on October 21, 2014, 02:58:54 PM

Concentration is moles per liter, isn't it?

yes conc = moles/ volume , but you are not told the volume of the gas? I am probably missing something obvious.

damn i am an idiot, the question tells me the pressure not the volume.. it has been a long night.

Title: Re: Calculating the concentration of a gas knowing the volume and temperature
Post by: jesss on October 21, 2014, 03:23:11 PM

Quote from: Borek on October 21, 2014, 02:58:54 PM

Concentration is moles per liter, isn't it?

Ah i see where you are going with this now, pV = nRT, so n/V  must equate to P/RT.

Thanks