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Kelvin or Celsius?

Posted: Sun Feb 09, 2020 10:03 pm
by Veronica Lu 2H
when using PV=nRT is the temperature supposed to be celsius or kelvin?

Re: Kelvin or Celsius?

Posted: Sun Feb 09, 2020 10:05 pm
by KSong_1J
I think you use Kelvin because the gas constant R always has Kelvin in the denominator so they cancel out!

Re: Kelvin or Celsius?

Posted: Sun Feb 09, 2020 11:01 pm
by Timmy Nguyen Dis 1I
Use Kelvin

Re: Kelvin or Celsius?

Posted: Sun Feb 09, 2020 11:21 pm
by Shrayes Raman
Kelvin... The gas constant R is listed in Kelvin so Kelvin is used in equation.

Re: Kelvin or Celsius?

Posted: Sun Feb 09, 2020 11:58 pm
by Alexis Robles 2k
Whenever it is T alone, you should use kelvin but when it is deltaT, you can use Celcius or kelvin.

Re: Kelvin or Celsius?

Posted: Mon Feb 10, 2020 12:02 am
by Venus_Hagan 2L
for the ideal gas equation use Kelvin but if you ever need the change in temperature it doesn't matter because both are scaled the same way

Re: Kelvin or Celsius?

Posted: Mon Feb 10, 2020 12:07 am
by gconcha
Kelvins are always used when applying the ideal gas law

The reason this is done is because Kelvins are more mathematically accurate in terms of chemically applying the excited state of the molecules in a gas to your calculations. zero K is the same as zero energy in the molecules, and is therefore the same as zero movement of the molecules. This is more mathematically correct than -273.15oC
If you really want, I'm sure you could look up values for the Ideal Gas Constant , but most are given in K because they're better for representing how the energy of the molecules affects the context.

Re: Kelvin or Celsius?

Posted: Sun Feb 16, 2020 9:10 pm
by Rosa Munoz 2E
Kelvin. it only doesn't matter if we are talking about change. If it is a capital T then it must be Kelvin

Re: Kelvin or Celsius?

Posted: Tue Feb 18, 2020 9:13 pm
by Juana Abana 1G
You would use kelvin.

Re: Kelvin or Celsius?

Posted: Tue Feb 18, 2020 9:20 pm
by Aarushi Solanki 4F
Kelvin, because the gas constant R is usually in terms of Kelvins.

Re: Kelvin or Celsius?

Posted: Tue Feb 18, 2020 9:36 pm
by 205405339
temperature is always kelvin

Re: Kelvin or Celsius?

Posted: Sun Feb 23, 2020 11:28 pm
by Jesse Anderson-Ramirez 3I
Should use Kelvin so the units match the constant.

Re: Kelvin or Celsius?

Posted: Sun Mar 01, 2020 8:57 pm
by Anish Natarajan 4G
Technically it's all dependent on the value of R that you use, but in most cases you'll be given a value that incorporates Kelvin rather than Celsius

Re: Kelvin or Celsius?

Posted: Sun Mar 01, 2020 8:58 pm
by Orrin Zhong 4G
Temperature is always Kelvin in PV = nRT.

Re: Kelvin or Celsius?

Posted: Sun Mar 01, 2020 8:58 pm
by AronCainBayot2K
Kelvin because the ideal gas constant is in terms of Kelvin not celsius.

Re: Kelvin or Celsius?

Posted: Sun Mar 01, 2020 9:28 pm
by CalvinTNguyen2D
You will almost always be using Kelvin in equations and calculations; in terms of the gas constant, it is measured in Kelvin rather than Celsius.

Re: Kelvin or Celsius?

Posted: Sun Mar 01, 2020 9:32 pm
by Celine 1F
Definitely use Kelvin

Re: Kelvin or Celsius?

Posted: Sun Mar 01, 2020 9:38 pm
by 105311039
you must use Kelvin because of the units in the gas constant R

Re: Kelvin or Celsius?

Posted: Sun Mar 01, 2020 11:46 pm
by Sean Tran 2K
Use Kelvin, as the gas constant R includes it.

Re: Kelvin or Celsius?

Posted: Mon Mar 02, 2020 8:03 am
by 605395381
kelvin, just make sure the units for R is the same

Re: Kelvin or Celsius?

Posted: Mon Mar 02, 2020 8:51 am
by AveryAgosto
You should use Kelvin because R uses Kelvin.

Re: Kelvin or Celsius?

Posted: Mon Mar 02, 2020 9:07 am
by Esha Chawla 2E
Veronica Lu 2H wrote:when using PV=nRT is the temperature supposed to be celsius or kelvin?


The units for R are L*atm/mol*K. Based on this information, we can determine that R should be in Kelvin.

In general, most chemical reactions use temperature in Kelvin.

Re: Kelvin or Celsius?

Posted: Mon Mar 02, 2020 10:12 am
by Aarushi Solanki 4F
It's supposed to be in Kelvin. Generally, we use Kelvin, but it is okay to use Celsius in equations involving the "change of T" since the scaling is the same for Kelvin and Celsius.

Re: Kelvin or Celsius?

Posted: Sat Mar 07, 2020 12:20 am
by Gurmukhi Bevli 4G
The temperature should be in kelvin.

Re: Kelvin or Celsius?

Posted: Sat Mar 07, 2020 12:26 am
by Brandi 2C
Since the STP (standard temperature and pressure) and R constant are in units of Kelvin, you should be using Kelvin for your calculations. If the problem does ask for the answer in units of Celsius, just do the calculations in Kelvin and then convert to Celsius after completing the calculations so you don't mess up unit calculations.

Re: Kelvin or Celsius?

Posted: Sat Mar 07, 2020 11:01 am
by Madeline Phan 1E
You use Kelvin since the units of R include Kelvin.

Re: Kelvin or Celsius?

Posted: Sat Mar 07, 2020 10:42 pm
by Yailin Romo 4G
Temperature is always in Kelvin, not Celsius.

Re: Kelvin or Celsius?

Posted: Sun Mar 08, 2020 6:40 pm
by Owen-Koetters-4I
kelvin

Re: Kelvin or Celsius?

Posted: Sun Mar 08, 2020 10:02 pm
by Areli C 1L
yup, as mentioned above, you would use Kelvin.

Re: Kelvin or Celsius?

Posted: Mon Mar 09, 2020 1:50 pm
by Justin Quan 4I
Veronica Lu 2H wrote:when using PV=nRT is the temperature supposed to be celsius or kelvin?

To add on, you use kelvin especially since the constant R is in kelvin, not celsius. However, if you use PV=nR∆T, the you may use either celsius or kelvin since the change in temperature would be the same.

Re: Kelvin or Celsius?

Posted: Mon Mar 09, 2020 1:54 pm
by Alfred Barrion 2H
You should use Kelvin since it matches with the gas constant R to cancel out.

Re: Kelvin or Celsius?

Posted: Mon Mar 09, 2020 2:10 pm
by 105335337
You use Kelvin because you must match the units within the R (gas constant) which uses kelvin.

Re: Kelvin or Celsius?

Posted: Mon Mar 09, 2020 2:18 pm
by pmokh14B
kelvin because the gas constant is always in terms of kelvin.

Re: Kelvin or Celsius?

Posted: Wed Mar 11, 2020 10:24 pm
by William Chan 1D
Kelvin. If the reaction happened at below 0°C, then the subsequent equation would be negative, having some weird consequences (i.e., negative pressure, negative volume).

Re: Kelvin or Celsius?

Posted: Wed Mar 11, 2020 10:25 pm
by Bryan Chen 1H
it depends on the unit of the gas constant. if its .08206 Latm/Kmol then use Kelvin, but another gas constant COULD have its units in celcius for whatever reason and then you should use celcius (but it probably will never ever come up in real life or a problem)

Re: Kelvin or Celsius?

Posted: Thu Mar 12, 2020 11:06 am
by Leonardo Le Merle 1D
Kelvin = Celsius + 273.15; the two are on the same scale so converting between the two isn't too tricky.

Re: Kelvin or Celsius?

Posted: Thu Mar 12, 2020 11:07 am
by Tanmay Singhal 1H
kelvin because the gas constant R is in K. sometimes it is in C and in that case u would use C

Re: Kelvin or Celsius?

Posted: Thu Mar 12, 2020 11:23 am
by Kavya Immadisetty 2B
Kelvin, just make sure all the units cancel

Re: Kelvin or Celsius?

Posted: Thu Mar 12, 2020 11:45 am
by Rodrigo2J
Kelvin

Re: Kelvin or Celsius?

Posted: Sun Mar 15, 2020 8:06 am
by Alan Cornejo 1a
Use kelvin and make sure your units match up.

Re: Kelvin or Celsius?

Posted: Sun Mar 15, 2020 12:50 pm
by Elizabeth Harty 1A
Kelvin

Re: Kelvin or Celsius?

Posted: Sun Mar 15, 2020 1:22 pm
by Anushka Chauhan2B
kelvin

Re: Kelvin or Celsius?

Posted: Mon Mar 16, 2020 6:10 pm
by Ayushi2011
Kelvin is always the unit for such equations.

Re: Kelvin or Celsius?

Posted: Mon Mar 16, 2020 7:12 pm
by Charlene Datu 2E
It's always in Kelvin because the R constant uses units of Kelvin

Re: Kelvin or Celsius?

Posted: Tue Mar 17, 2020 12:27 pm
by BAlvarado_1L
kelvin so it cancels out with the units of R

Re: Kelvin or Celsius?

Posted: Tue Mar 17, 2020 8:42 pm
by SVajragiri_1C
You use Kelvin, because the unit for R in this equation has K in it.

Re: Kelvin or Celsius?

Posted: Tue Mar 17, 2020 9:31 pm
by EllieSchmidtke_4I
Use Kelvin since this is the SI unit for temperature.

Re: Kelvin or Celsius?

Posted: Tue Mar 17, 2020 10:19 pm
by Bella Townsend
Typically, you only ever use celsius is there is a change in temperature (delta T) because then the units don't matter. The difference will be the same.