Temperature


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Sophia Dinh 1D
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Joined: Thu Jul 25, 2019 12:15 am

Temperature

Postby Sophia Dinh 1D » Wed Jan 29, 2020 10:30 am

Do you need to convert the temperature to Kelvin?

vibha gurunathan 1h
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Joined: Mon Oct 07, 2019 12:15 am

Re: Temperature

Postby vibha gurunathan 1h » Wed Jan 29, 2020 11:31 am

It depends on the units of the constants in the problem. If it's a problem with molar heat capacity, use kelvin. If specific heat capacity, you would use celsius. Furthermore, usually you'd do delta T, which either would work. The ideal gas law, however, is always in kelvin, and usually if they ask for just "T" it'd be in kelvin.

romina_4C
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Joined: Thu Jul 11, 2019 12:17 am

Re: Temperature

Postby romina_4C » Wed Jan 29, 2020 12:14 pm

Usually the question will specify. If you are not sure whether to use Kelvin or Celsius, an easy way of checking is to see what the units are for the other numbers or constants in your equation to see if they have Kelvin or Celsius in them. Depending on which one they use, you may or may not have to convert.

Angela Patel 2J
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Joined: Sat Aug 24, 2019 12:17 am

Re: Temperature

Postby Angela Patel 2J » Wed Jan 29, 2020 12:26 pm

Is it ok to use either since we only care about the change in temperature? The change in temperature will be the same whether measured in kelvin or celsius.

Daria MacAuslan 1H
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Joined: Sat Aug 17, 2019 12:16 am

Re: Temperature

Postby Daria MacAuslan 1H » Wed Jan 29, 2020 12:29 pm

most equations in chemistry tend to use Kelvin instead of Celcius or Farenheit. This is important for these calculations because without conversion, the answers to some questions may come out incorrectly. Usually, if the question does not want you to use Kelvin, it will let you know.

Orrin Zhong 4G
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Joined: Sat Jul 20, 2019 12:16 am

Re: Temperature

Postby Orrin Zhong 4G » Fri Jan 31, 2020 6:59 pm

Most of the time, temperature has to be changed to Kelvin to be plugged into a formula. However, when an formula requires the change in temperatures (such as in q = mcdeltaT), the use of Celsius for the initial and final temperatures are acceptable because the scaling factor from Celsius to Kelvin cancels out in the subtraction. However, you should convert the temperature you get from the formula into whatever units the question wants you to put your answer in.

kim 2I
Posts: 105
Joined: Thu Jul 25, 2019 12:17 am

Re: Temperature

Postby kim 2I » Fri Jan 31, 2020 9:09 pm

When referring to the change in temperature, you do not have to worry about the units (Kelvin or celsius) on the temperature. The change would be the same regardless and would not affect your calculations.

Sanjana Borle 2K
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Joined: Fri Aug 09, 2019 12:15 am

Re: Temperature

Postby Sanjana Borle 2K » Fri Jan 31, 2020 9:39 pm

It does not matter for the most part because the change in temperature in one degree of Celsius is the same as the change in temperature in one degree of Kelvin.

Pablo 1K
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Joined: Sat Feb 02, 2019 12:15 am

Re: Temperature

Postby Pablo 1K » Fri Jan 31, 2020 9:42 pm

It depends on the units that the question is asking for. But you should be good as a drop of 1 degree in K is same as in C

Nathan Rothschild_2D
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Joined: Fri Aug 02, 2019 12:15 am

Re: Temperature

Postby Nathan Rothschild_2D » Sun Feb 02, 2020 9:29 pm

For PV=nRT you must convert temperature to kelvin, so to be safe, unless the equation you're using involves celsius, convert to kelvin.

EllieSchmidtke_4I
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Joined: Wed Feb 20, 2019 12:16 am

Re: Temperature

Postby EllieSchmidtke_4I » Sun Feb 02, 2020 9:31 pm

Since Kelvin is the SI units for temperature, it is ideal to convert your answer to Kelvin.

Gabriella Bates 2L
Posts: 113
Joined: Thu Jul 11, 2019 12:15 am

Re: Temperature

Postby Gabriella Bates 2L » Sun Feb 02, 2020 9:58 pm

Most questions will require you to convert to Kelvin, since this is the S.I. unit. However, if the question asks for the change in temperature, delta T, then it's unnecessary to change the units. This is because Celsius and kelvin have the same magnitude, so the change in temperature will be the same.

saigorijavolu2k
Posts: 108
Joined: Sat Sep 28, 2019 12:15 am

Re: Temperature

Postby saigorijavolu2k » Sun Feb 02, 2020 10:05 pm

Kelvin and Celsius increment by the same number, so in certain cases where units cancel out like q=mcdeltt it is valid. In a case where you are not sure, switch to kelvin.

Jesse Anderson-Ramirez 3I
Posts: 54
Joined: Thu Sep 26, 2019 12:18 am

Re: Temperature

Postby Jesse Anderson-Ramirez 3I » Wed Feb 05, 2020 10:33 am

If the question asks for the change in temperature you can use either. If not, you need to look at what units are used in the question or which units are used in the constants.

Jasmine Vallarta 2L
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Joined: Sat Aug 17, 2019 12:18 am

Re: Temperature

Postby Jasmine Vallarta 2L » Wed Feb 05, 2020 11:15 am

it depends on the units given/what they ask for

Brandi 2C
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Joined: Thu Feb 28, 2019 12:15 am

Re: Temperature

Postby Brandi 2C » Fri Feb 07, 2020 11:56 pm

As many students started above, K is usually your best bet. The reason for this, however, is that K is an SI unit and therefore is usually used in multiple occasions/circumstances unless it is specifically stated that the answer should be in C or even F. My old high school chemistry teacher ingrained in our minds that SI units are always the go to standard unless started otherwise

Phuong Tran 1G
Posts: 33
Joined: Sat Sep 14, 2019 12:16 am

Re: Temperature

Postby Phuong Tran 1G » Sat Feb 08, 2020 12:00 am

Kelvin is usually the units that they ask you for. However, depending on the problem, using kelvin or Celsius would not matter if you are looking for the change between the initial and final

Nuoya Jiang
Posts: 99
Joined: Sat Sep 14, 2019 12:17 am

Re: Temperature

Postby Nuoya Jiang » Sat Feb 08, 2020 11:56 am

Most of the time yes, because you have to cancel the units in the gas constant R. But when you are calculation the difference between temperatures, for example, in the equation involving heat capacity, you don't have to worry about that.


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