### P=(n/v)RT

Posted:

**Sun Jan 12, 2020 4:41 pm**I see that there is the equation P= (n/v)RT which is connected to PV=nRT but why is it that V (volume) is not divided by the whole nRT? Since its only dividing by n (number of moles).

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=123&t=56073

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Posted: **Sun Jan 12, 2020 4:41 pm**

I see that there is the equation P= (n/v)RT which is connected to PV=nRT but why is it that V (volume) is not divided by the whole nRT? Since its only dividing by n (number of moles).

Posted: **Sun Jan 12, 2020 5:03 pm**

I think it just means concentration multiplied by the constant and temperature

Posted: **Sun Jan 12, 2020 5:12 pm**

n/V is the same as (nRT)/V!

Posted: **Sun Jan 12, 2020 6:04 pm**

n/V is also a way of writing molarity since its units are mols/L. This is nice for understanding how you can use the ideal gas equation to determine Kc as well I believe.

Posted: **Sun Jan 12, 2020 6:20 pm**

You can get the same answer either way you write it but using P=(n/V)RT makes it easier when you need to convert between the concentration and partial pressure of a compound.

Posted: **Sun Jan 12, 2020 6:25 pm**

I believe this depends on your given values and what you are trying to find.The equation is rearranged to find Kc. (P=nRT/V = n/V x RT = conc x RT)

Posted: **Sun Jan 12, 2020 6:41 pm**

V is also divided by PRT :) it's just typed (n/V)RT for it be easily seen as concentration * RT. (nRT)/V means the same thing

Posted: **Sun Jan 12, 2020 6:53 pm**

n/V is how concentration is calculated and the derived equation includes concentration. I believe it is written that way to show that it means concentration.

Posted: **Sun Jan 12, 2020 9:06 pm**

So basically you're just multiplying the molarity times RT which gives you P?

Posted: **Sun Jan 12, 2020 9:08 pm**

Ruby Richter 2L wrote:So basically you're just multiplying the molarity times RT which gives you P?

Yea that's all you're doing.

Posted: **Sun Jan 12, 2020 9:18 pm**

Writing (n/V)RT is the same as nRT/V

Posted: **Sun Jan 12, 2020 9:35 pm**

You can use this equation to calculate for concentration, given that concentration is calculated by dividing moles by volume (n/v).

Posted: **Mon Jan 13, 2020 9:57 am**

You can write it as V is being divided by the whole thing (P = nRT/v). I think why Dr. Lavelle has been writing the V specifically under the n was just emphasize that n/v is molarity, and therefore the concentration.