converting T to kelvin

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Deja Nora
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Joined: Fri Sep 28, 2018 12:22 am

converting T to kelvin

Postby Deja Nora » Tue Feb 18, 2020 8:24 pm

When calculating something involving changing temperature, it is okay to leave the temperature in celsius correct?

Alexis Webb 2B
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Joined: Thu Jul 11, 2019 12:15 am

Re: converting T to kelvin

Postby Alexis Webb 2B » Tue Feb 18, 2020 8:41 pm

It depends on the units you are solving for and any other units involved in the equation by other constants, etc. Can you give a specific instance that you have a question about?

Esha Chawla 2E
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Re: converting T to kelvin

Postby Esha Chawla 2E » Tue Feb 18, 2020 8:51 pm

Deja Nora wrote:When calculating something involving changing temperature, it is okay to leave the temperature in celsius correct?


That's correct - because change in degrees celsius is the same as the change in degrees Kelvin, you can leave the temperature in celsius. For example, if given a q=mC(delta T) problem, you can keep the T in celsius.

Hiba Alnajjar_2C
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Re: converting T to kelvin

Postby Hiba Alnajjar_2C » Tue Feb 18, 2020 8:52 pm

The change in temperature would be the same for Celsius and Kelvin (if you convert to Kelvin and calculate the difference, you'll notice it's the same as the difference in Celsius). However, if it's just temperature (such as in delta G = -RTlnK), I believe that you have to convert to whatever units the constant is in.

Jack Riley 4f
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Re: converting T to kelvin

Postby Jack Riley 4f » Tue Feb 18, 2020 8:56 pm

when talking about delta T then yes it is ok because they are the same in that respect. However, when doing calculations with T you should convert to K because most R values are given with K as the unit

Harry Zhang 1B
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Re: converting T to kelvin

Postby Harry Zhang 1B » Tue Feb 18, 2020 9:07 pm

If it's merely change in temperature, yes, because the conversion to K by adding 273.15 will cancel out. However, if you are using it like 1/T2-1/T1, then you will have to convert it.

Venus_Hagan 2L
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Re: converting T to kelvin

Postby Venus_Hagan 2L » Tue Feb 18, 2020 9:12 pm

If you are considering delta T then it is okay to leave in Celcius because both units have the same scale, but if you are just considering temperature then you should convert to kelvins by adding 273.15

Aarushi Solanki 4F
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Joined: Sat Jul 20, 2019 12:17 am

Re: converting T to kelvin

Postby Aarushi Solanki 4F » Tue Feb 18, 2020 9:20 pm

If the question specifies a temperature unit then use the given one. Otherwise, remember to perform your calculations with like-temperature units, so they correctly cancel out based on ratios.

Nick Fiorentino 1E
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Re: converting T to kelvin

Postby Nick Fiorentino 1E » Wed Feb 19, 2020 5:56 pm

I think it's important to convert C to K just to be safe; a lot of times using K will make it so the units cancel, so I just always convert C to K to be safe

Amir Bayat
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Joined: Sat Sep 07, 2019 12:16 am

Re: converting T to kelvin

Postby Amir Bayat » Wed Feb 19, 2020 6:09 pm

It usually depends on the units of Rydberg's constant as well. If you want to use an equation where Rydberg's constant is in K, which in most equations it is, make sure to convert, if not, then there is no need to convert. Therefore, always look at the units of Rydberg's constant, this is why is is always important to write out the units when solving the problem.

Kylie Lim 4G
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Joined: Sat Aug 17, 2019 12:15 am

Re: converting T to kelvin

Postby Kylie Lim 4G » Wed Feb 19, 2020 6:17 pm

Changes in temperature are fine since they will be the same for kelvin and celsius. The only time when you have to worry about converting between celsius and kelvin is if the problem specifically asks for the answer in terms of one, or if you are using a constant like R in PV = NRT when R is specifically in kelvin.

Brandon Valafar
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Re: converting T to kelvin

Postby Brandon Valafar » Wed Feb 19, 2020 6:54 pm

Usually depends on the units in the given in the problem and what equation the problem entails in using. I usually always conver from C to K just to be safe unless it asks for it in units celsius.

Sally Qiu 2E
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Joined: Fri Aug 30, 2019 12:18 am

Re: converting T to kelvin

Postby Sally Qiu 2E » Wed Feb 19, 2020 6:55 pm

it's okay to leave the temperature in celsius if you're just finding the change-- it shouldnt make a difference mathematically

Bryan Chen 1H
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Joined: Mon Jun 17, 2019 7:24 am

Re: converting T to kelvin

Postby Bryan Chen 1H » Wed Feb 19, 2020 11:06 pm

i would always use the equation sheet and look at the units, especially for constants. for example, .08206 = R, R has units in L, atm, K, and mol. So, on a test you should make sure when plugging into PV=nRT, for example, to match up those units to the R constant.

BritneyP- 2c
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Joined: Sat Sep 14, 2019 12:15 am

Re: converting T to kelvin

Postby BritneyP- 2c » Wed Feb 19, 2020 11:09 pm

It depends on the units of your other constants. If you use 8.314 j/mol*K, then you have to convert to kelvin. If you are finding the difference between them though it doesn't matter because the end result is the same number

Jainam Shah 4I
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Re: converting T to kelvin

Postby Jainam Shah 4I » Thu Feb 20, 2020 6:41 pm

If the question is asking for temperature and doesn't specify units you can use either celsius or kelvin. If you are doing calculations then be careful to see the units given in the constant and use kelvin or celsius accordingly

Tiffany_Chen 2K
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Re: converting T to kelvin

Postby Tiffany_Chen 2K » Thu Feb 20, 2020 8:25 pm

If the question asks for the answer to be in specific units, don't forget to convert at the end. For thermodynamics, usually celsius/kelvin can be interchangeable due to the same difference.

Minh Ngo 4G
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Joined: Thu Jul 25, 2019 12:17 am

Re: converting T to kelvin

Postby Minh Ngo 4G » Thu Feb 20, 2020 9:54 pm

Depends on the equation you are using but I think if in doubt, just convert it to K (unless they are problems that involve a specific heat capacity ones)

Verity Lai 2K
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Joined: Sat Aug 24, 2019 12:18 am

Re: converting T to kelvin

Postby Verity Lai 2K » Sat Feb 22, 2020 10:51 am

I think the only time its okay to keep temperature in Celsius is when the units are in celsius or when you are calculating delta t because the change in Celsius is the same as the change in kelvin.

Rodrigo2J
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Re: converting T to kelvin

Postby Rodrigo2J » Sat Feb 22, 2020 11:04 am

You use celsius and kelvin depending on the units of the other constants being used.

Madeline Phan 1E
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Re: converting T to kelvin

Postby Madeline Phan 1E » Sat Feb 22, 2020 12:09 pm

It is okay to leave the temperature in Celsius or Kelvin when calculating delta T because the number of units that increase or decrease will remain the same no matter what.

AronCainBayot2K
Posts: 101
Joined: Fri Aug 30, 2019 12:17 am

Re: converting T to kelvin

Postby AronCainBayot2K » Sat Feb 22, 2020 2:02 pm

T to kelvin should only be applied when the the problem involves using constants or equations that use Kelvin instead of Temperature. In ideal gas law equations, you would use Kelvin (+273.15) if given celcsius.


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