T variable in pv=nrt  [ENDORSED]


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Bryce Ramirez 1J
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T variable in pv=nrt

Postby Bryce Ramirez 1J » Sat Mar 14, 2020 9:29 pm

For the temperature in every calculation using the ideal gas formula, will it always be in Kelvin or will there be times where it is in Celcius? I know that the units have to cancel from the gas constant, but I'm not sure if there is any gas constant that requires celcius instead of Kelvin.

vpena_1I
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Re: T variable in pv=nrt

Postby vpena_1I » Sat Mar 14, 2020 9:38 pm

All gas constants are in Kelvin, so unless you really wanted to convert these to Celsius, its easier to convert Celsius to kelvin from the get-go.

Zoya Mulji 1K
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Re: T variable in pv=nrt

Postby Zoya Mulji 1K » Sat Mar 14, 2020 9:42 pm

you should probably always keep it in Kelvin just to be safe because if it cancels out it won't matter anyways.

SMIYAZAKI_1B
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Re: T variable in pv=nrt

Postby SMIYAZAKI_1B » Sat Mar 14, 2020 9:44 pm

It is better to keep it in Kelvin just because of the unit of the gas constant, R, has Temperature in Kelvin. In order to cancel out the units, you really have to make sure that units match and if you really really need Celcius, make sure to change the unit after figuring the Kelvin.

Alfred Barrion 2H
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Re: T variable in pv=nrt

Postby Alfred Barrion 2H » Sat Mar 14, 2020 10:10 pm

For simplicity, it would be easier to use Kelvin, especially since Kelvin is used in the constants.

Frank He 4G
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Re: T variable in pv=nrt

Postby Frank He 4G » Sat Mar 14, 2020 10:14 pm

We should always work in kelvin just to be safe, so I'd convert to kelvin if needed and keep it that way. If the problem asks for a value using Celsius, then convert it back at the end.

Katie Kyan 2K
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Re: T variable in pv=nrt

Postby Katie Kyan 2K » Sat Mar 14, 2020 10:39 pm

I think I would keep the units in Kelvin because this is usually what we work with and most likely the temperature will be given to you in Kelvin.

Alan Cornejo 1a
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Re: T variable in pv=nrt

Postby Alan Cornejo 1a » Sun Mar 15, 2020 6:58 am

Using kelvin is most advisable as it is an easy conversion, and it allows for the matchup of all the right units for your equation.

KHowe_1D
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Re: T variable in pv=nrt

Postby KHowe_1D » Sun Mar 15, 2020 7:17 am

Since Kelvin would be canceled out by the units of R, you should convert all temperatures to K.

Nawal Dandachi 1G
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Re: T variable in pv=nrt

Postby Nawal Dandachi 1G » Sun Mar 15, 2020 7:20 am

You should convert temperature to kelvin because you are using R which uses Kelvin.

Gurmukhi Bevli 4G
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Re: T variable in pv=nrt

Postby Gurmukhi Bevli 4G » Tue Mar 17, 2020 11:48 pm

I would keep it in Kelvin at all times, just to be safe.

My-Lan Le 1L
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Re: T variable in pv=nrt

Postby My-Lan Le 1L » Mon Jan 04, 2021 3:52 pm

It should be in Kelvin so that the the units of T can match the units of R.

Jack_Pearce_2H
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Re: T variable in pv=nrt

Postby Jack_Pearce_2H » Mon Jan 04, 2021 4:03 pm

They're always supposed to be in Kelvin, not Celsius.

Karl Yost 1L
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Re: T variable in pv=nrt  [ENDORSED]

Postby Karl Yost 1L » Mon Jan 04, 2021 10:23 pm

Conventionally, the gas constant units are all in Kelvin. Since we typically want the temperature units to cancel out when performing calculations (unless we're explicitly solving for temperature, T will also be in Kelvin to ensure that the temperature units from R and T do indeed cancel.

Adam Bustamante 1I
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Re: T variable in pv=nrt

Postby Adam Bustamante 1I » Tue Jan 05, 2021 9:55 pm

I would leave the temperature in Kelvin for its units because that is the correct unit when using ideal gas laws.

annabelchen2a
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Re: T variable in pv=nrt

Postby annabelchen2a » Wed Jan 06, 2021 1:56 pm

My thinking from high school chemistry was for temperature in the ideal gas law, you need to use a scale that starts at absolute zero - and the Kelvin scale does that.
If you were to use the Celsius scale and used a temperature equivalent of one below 273K, then you'd have a negative volume or pressure which just doesn't make sense. So I believe Kelvin is just the easiest scale/unit to use.

Shreyank Kadadi 3K
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Re: T variable in pv=nrt

Postby Shreyank Kadadi 3K » Wed Jan 06, 2021 3:14 pm

If you wanted to use Celsius, you would have to convert the gas constant (R) accordingly. I would recommend staying in Kelvin!

Adalia 3E
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Re: T variable in pv=nrt

Postby Adalia 3E » Wed Jan 06, 2021 3:19 pm

It's probably easier to convert from Celsius to Kelvin so that you only need to memorize one R constant rather than both R constants

jessicasilverstein1F
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Re: T variable in pv=nrt

Postby jessicasilverstein1F » Wed Jan 06, 2021 3:21 pm

It will always be in Kelvin. Be sure to make sure this is the value you have.

Madison Muggeo 3H
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Re: T variable in pv=nrt

Postby Madison Muggeo 3H » Thu Jan 07, 2021 1:30 pm

Hi! The temperature should always be in Kelvin because all gas constants use Kelvin as their unit for temperature so it's just easier. :)

Rahul Sobti 1E
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Re: T variable in pv=nrt

Postby Rahul Sobti 1E » Thu Jan 07, 2021 1:38 pm

Temperature should always be in Kelvin because that is how all the other variables units will cancel out with. If you make it Celsius, you will have to change the units of the whole equation or of other units to compensate. I think people like to use Kelvin because it is only zero at absolute zero whereas Celsius is zero at a relatively normal temperature, so it makes calculations more accurate by using Kelvin.

Chudi Onyedika 3A
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Re: T variable in pv=nrt

Postby Chudi Onyedika 3A » Sat Jan 09, 2021 1:06 pm

You should stick with Kelvin as the unit of temperature in this equation.

Sophia Spungin 2E
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Re: T variable in pv=nrt

Postby Sophia Spungin 2E » Sat Jan 09, 2021 1:13 pm

As people have mentioned, I would always use temperature in Kelvin as the alternative would be changing the units on the constants and pressure values. Its super simple to convert from Celsius to Kelvin if the temperature happens to be given in Celsius, all you have to do is take the temperature in Celsius and add 273.15 to convert to Kelvin.

Juliana Rosales 1H
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Re: T variable in pv=nrt

Postby Juliana Rosales 1H » Sun Jan 10, 2021 9:51 pm

I would say always to assume kelvin unless Celsius is specified.

Nick Saeedi 1I
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Re: T variable in pv=nrt

Postby Nick Saeedi 1I » Sun Jan 10, 2021 10:02 pm

I usually tend to keep it in Kelvin.

Joshua_Chan_3K
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Re: T variable in pv=nrt

Postby Joshua_Chan_3K » Sun Jan 10, 2021 10:12 pm

I don't think its possible for you to ever find a gas law with the units in Celsius because the unit conversion from Celsius to Kelvin is a addition and not multiplication. It just wouldn't be possible to factor that into the unit calculations.

DominicMalilay 1F
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Re: T variable in pv=nrt

Postby DominicMalilay 1F » Sun Jan 10, 2021 10:14 pm

I personally never keep my units in celsius for the t variable as its just easier to remember!

Alejandro Gonzalez 2G
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Re: T variable in pv=nrt

Postby Alejandro Gonzalez 2G » Sun Jan 10, 2021 10:59 pm

I think it's easier to keep the t units in Kelvin in the long run.

Jared Limqueco 3E
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Re: T variable in pv=nrt

Postby Jared Limqueco 3E » Sun Jan 10, 2021 11:00 pm

Most of the time it is in Kelvin.

Mina Tadros 3L
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Re: T variable in pv=nrt

Postby Mina Tadros 3L » Sun Jan 10, 2021 11:01 pm

When dealing with the ideal gas law, you must always use kelvin for temperature.

Brandon McClelland3L
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Re: T variable in pv=nrt

Postby Brandon McClelland3L » Sun Jan 10, 2021 11:02 pm

You will probably always use Kelvin. The equation doesn't work unless the unit for temperature has absolute zero = 0.

Gustavo_Chavez_1K
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Re: T variable in pv=nrt

Postby Gustavo_Chavez_1K » Sun Jan 10, 2021 11:05 pm

Dr. Lavelle stated in lecture that we will almost always use Kelvin when working with temperature in equations.

reyvalui_3g
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Re: T variable in pv=nrt

Postby reyvalui_3g » Tue Jan 12, 2021 8:07 pm

It will always be un Kelvin.

Tiao Tan 3C
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Re: T variable in pv=nrt

Postby Tiao Tan 3C » Thu Jan 14, 2021 1:21 am

T must always be in Kelvin. But if you are given in Celcius, you can convert it into Kelvin with the equation Kelvin = Celsius + 273.15.

Pranav Daggubati 3C
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Re: T variable in pv=nrt

Postby Pranav Daggubati 3C » Thu Jan 14, 2021 8:30 am

T is always in Kelvin because the gas constant r has a kelvin unit in it.

Tikva Cohen 1K
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Re: T variable in pv=nrt

Postby Tikva Cohen 1K » Thu Jan 14, 2021 12:06 pm

It has to be in Kelvin in order to cancel out the units, but if you're given something else you can just convert it.

MariaCassol1L
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Re: T variable in pv=nrt

Postby MariaCassol1L » Fri Jan 15, 2021 5:49 pm

It should always be in Kelvin if the problem gives you temperature units in Celsius you should convert it before plugging it in.

ShinwooKim_3E
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Re: T variable in pv=nrt

Postby ShinwooKim_3E » Sat Jan 16, 2021 1:32 pm

Always keep the units in Kelvin so you don't accidently miscalculate.

Sameer Chowdhury 3C
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Re: T variable in pv=nrt

Postby Sameer Chowdhury 3C » Sun Jan 17, 2021 6:39 pm

For the T in pv=nrt, it should always stay in Kelvin.


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