q=mCΔT vs q=nCΔT
Moderators: Chem_Mod, Chem_Admin
-
- Posts: 100
- Joined: Fri Sep 24, 2021 7:09 am
q=mCΔT vs q=nCΔT
Can we use q=mCΔT and q=nCΔT interchangeably when we're given the sample either in grams or mols? Like we wouldn't have to do any conversions from mols to grams and vice versa?
-
- Posts: 112
- Joined: Fri Sep 24, 2021 6:39 am
Re: q=mCΔT vs q=nCΔT
You can use grams when the heat capacity given is Joules/gK and moles when it is Joules/molsK.
-
- Posts: 101
- Joined: Fri Sep 24, 2021 6:34 am
Re: q=mCΔT vs q=nCΔT
Yep, if you are given mols you can use q=nCΔT and if you are given the mass in grams you can use q=mCΔT!
Re: q=mCΔT vs q=nCΔT
These equations will give you the same value in kJ or J. However, the heat capacity constant C changes depending on if you're using moles of molar mass. For molar mass, you will have to use the specific heat capacity with units (kJ/(K*g)), and for moles, you will use molar heat capacity with the units (kJ/(K*mol)). Do note that the heat capacities will sometimes be in joules, so just pay careful attention to units. If the units don't make sense at the end then maybe give the question another look. Hope this helps!
-
- Posts: 100
- Joined: Fri Sep 24, 2021 6:21 am
- Been upvoted: 1 time
Re: q=mCΔT vs q=nCΔT
Hello. So essentially both equations will give you the same outcome but the only difference will be in your units. So if you want your units to add up you would utilize the respective equation. Hope this helps.
-
- Posts: 101
- Joined: Fri Sep 24, 2021 5:42 am
Re: q=mCΔT vs q=nCΔT
You would use m if you have the specific heat capacity and n if you have the molar heat capacity.
-
- Posts: 100
- Joined: Fri Sep 24, 2021 6:31 am
Re: q=mCΔT vs q=nCΔT
If you're given the sample in both moles and grams, then it should be fine to use either form of the equation. However, be careful to notice whether heat capacity or specific heat capacity is given. If heat capacity is given, then the equation would be q = CdeltaT
Re: q=mCΔT vs q=nCΔT
Yes, they can pretty much be used interchangeably. Use q=mCΔT when you have specific heat capacity / mass. Use q=nCΔT when you have molar capacity / moles.
-
- Posts: 145
- Joined: Fri Sep 24, 2021 5:45 am
Re: q=mCΔT vs q=nCΔT
If you are given moles in the question, you would use q=nCΔT. If you were given grams in the question, you would use q=mCΔT. However, it is possible to convert from one to the other. You would have to pay attention to units and convert how you would from grams to moles and vice versa. Hope this helps!
-
- Posts: 113
- Joined: Fri Sep 24, 2021 6:27 am
Re: q=mCΔT vs q=nCΔT
They are both the same equation, aka finding the heat entering/exiting the system, but the units expressed are different.
When given the specific heat capacity, you will have to use the first equation, q =mCΔT so that the units of matter cancel out since specific heat capacity has units kJ/(K*g). When given the molar heat capacity, you will have to use the second equation, q=nCΔT since the molar heat capacity has units kJ/(K*mol).
When given the specific heat capacity, you will have to use the first equation, q =mCΔT so that the units of matter cancel out since specific heat capacity has units kJ/(K*g). When given the molar heat capacity, you will have to use the second equation, q=nCΔT since the molar heat capacity has units kJ/(K*mol).
-
- Posts: 100
- Joined: Fri Sep 24, 2021 7:13 am
Re: q=mCΔT vs q=nCΔT
They essentially mean the same thing (amount of heat) but choose which equation depending on the units of the given. Specific heat capacity will give you m, and molar heat capacity gives n. Just make sure all units cancel out.
-
- Posts: 107
- Joined: Fri Sep 24, 2021 5:02 am
Re: q=mCΔT vs q=nCΔT
You can use either equation, but the C constant will be different based on if you're inputing grams or moles. Just make sure that all of the units match.
-
- Posts: 66
- Joined: Fri Sep 24, 2021 7:24 am
Re: q=mCΔT vs q=nCΔT
These equations will essentially give you the same answers, the only real difference is the units. m is for moles and n is for grams, this is due to the units of the heat capacity. If you are solving for the heat capacity it would just change the units of your answer but both could be used to solve.
-
- Posts: 95
- Joined: Fri Sep 24, 2021 6:41 am
Re: q=mCΔT vs q=nCΔT
Yes you can. But usually it's better to stick with the ones you're given. If you're given values in grams, you should use mC(delta T) and if you're given values in moles you should use nC(delta T).
-
- Posts: 99
- Joined: Fri Sep 24, 2021 7:15 am
Re: q=mCΔT vs q=nCΔT
You would decide which equation to use based on what units the heat capacity is in. They are both used the same way, but you just have to make sure your units are consistent.
-
- Posts: 75
- Joined: Mon Jan 03, 2022 9:26 pm
Re: q=mCΔT vs q=nCΔT
You can use them interchangeably as long as the question provides you with either mols or grams, but you can only convert them by knowing the molar mass, so if the question says something vague like "in this sample", you can't change it. I would just use what it gives you unless you have to convert for the answer.
-
- Posts: 102
- Joined: Fri Sep 24, 2021 5:06 am
Re: q=mCΔT vs q=nCΔT
What helps is to look at the units of the values you are given to choose which value of C to use with either the mass or the moles
-
- Posts: 144
- Joined: Fri Sep 24, 2021 7:31 am
Re: q=mCΔT vs q=nCΔT
Use q=mCΔT when you're given the sample in grams and have the specific heat capacity. Use q=nCΔT when you're given the sample in moles and have the molar heat capacity. The easiest way to know which equation to use is to write out the units and make sure they cancel to give you q in J or KJ.
-
- Posts: 99
- Joined: Fri Sep 24, 2021 6:06 am
-
- Posts: 101
- Joined: Fri Sep 24, 2021 6:40 am
- Been upvoted: 1 time
-
- Posts: 104
- Joined: Fri Sep 24, 2021 6:54 am
Re: q=mCΔT vs q=nCΔT
They essentially mean the same. m is in grams, so make sure you use the right Cp value (in grams), n is in moles so be sure to use the Cp value in moles for this one. Either way, you end up with q, just be aware of your units.
-
- Posts: 102
- Joined: Fri Sep 24, 2021 5:28 am
- Been upvoted: 1 time
Re: q=mCΔT vs q=nCΔT
Yes, the equations are interchangeable, but just be careful to use the correct C value!
-
- Posts: 101
- Joined: Fri Sep 24, 2021 6:57 am
Re: q=mCΔT vs q=nCΔT
n = moles and m = mass.
So depending on if the sample in the problem / heat capacity is in grams or moles (or you may have to convert), you would use the corresponding one.
So depending on if the sample in the problem / heat capacity is in grams or moles (or you may have to convert), you would use the corresponding one.
-
- Posts: 104
- Joined: Fri Sep 24, 2021 5:53 am
Re: q=mCΔT vs q=nCΔT
In the case that you are given moles, you would use q=nCΔT, while if you are given the mass in grams you can use q=mCΔT
-
- Posts: 107
- Joined: Fri Sep 24, 2021 6:05 am
Re: q=mCΔT vs q=nCΔT
q=mCΔT is used when C is given in terms of J/gC
q=nCΔT is used when C is given in terms of J/molC
q=nCΔT is used when C is given in terms of J/molC
-
- Posts: 111
- Joined: Fri Sep 24, 2021 5:12 am
Re: q=mCΔT vs q=nCΔT
Furthermore, to add to the discussion, heat capacity is an extensive property since it depends on the amount of the substance. However, specific heat capacity and molar heat capacity are intensive properties since they are the same regardless of the amount of the substance.
-
- Posts: 51
- Joined: Mon Jan 03, 2022 10:36 am
Re: q=mCΔT vs q=nCΔT
You use mols with molar heat capacity and mass with specific heat capacity to get the correct units. and for calorimeter you include neither moles or mass
-
- Posts: 51
- Joined: Wed Feb 17, 2021 12:21 am
Re: q=mCΔT vs q=nCΔT
Essentially you will have the same value just in different units. J/gC if you are using mass units and J/mC if you are using moles.
-
- Posts: 102
- Joined: Fri Sep 24, 2021 5:07 am
Re: q=mCΔT vs q=nCΔT
Both equations can be used interchangeably, it really just depends on what units the question or situation gives you as well as what you are trying to solve for. If the question gives you mass in grams then you use m. If the question gives you number of moles, then use n.
-
- Posts: 99
- Joined: Fri Sep 24, 2021 6:39 am
Re: q=mCΔT vs q=nCΔT
yes you do not have to convert between moles and grams. the variable n has units of moles and the variable m is used for the mass in grams.
-
- Posts: 100
- Joined: Fri Sep 24, 2021 7:36 am
Re: q=mCΔT vs q=nCΔT
As others previously stated, we should match the unit of the heat capacity given (either moles or mass),
-
- Posts: 101
- Joined: Fri Sep 24, 2021 6:58 am
-
- Posts: 101
- Joined: Fri Sep 24, 2021 6:54 am
Re: q=mCΔT vs q=nCΔT
Hi! The only difference is the units! We use q=mCΔT when C is given in terms of J/gC and q=nCΔT when C is given in terms of J/molC.
Re: q=mCΔT vs q=nCΔT
You would use mass if you have the specific heat capacity and if you have the molar heat capacity, use moles (n)
Re: q=mCΔT vs q=nCΔT
You would use mass if you have the specific heat capacity and if you have the molar heat capacity, use moles (n)
-
- Posts: 52
- Joined: Mon Jan 03, 2022 10:34 am
Re: q=mCΔT vs q=nCΔT
HI! They are essentially the same equation but it just depends on the units
you would use the q=mCdeltaT equation if you're given grams and in turn, you would use the q=nCdeltaT equation if you're given moles
you would use the q=mCdeltaT equation if you're given grams and in turn, you would use the q=nCdeltaT equation if you're given moles
-
- Posts: 112
- Joined: Fri Sep 24, 2021 6:10 am
-
- Posts: 104
- Joined: Fri Sep 24, 2021 7:16 am
Re: q=mCΔT vs q=nCΔT
Make sure you look at the units C is given in! This will determine which equation to use. If given enough information, you can convert between moles and grams and choose which equation to use.
-
- Posts: 100
- Joined: Fri Sep 24, 2021 6:35 am
Re: q=mCΔT vs q=nCΔT
It's the same thing! Just make sure that you are sure of the units that are being used, n usually refers more to molarity and concentration while m usually refers to mass, which would be in grams. As long as the units for the specific heat matches, you are good.
-
- Posts: 49
- Joined: Fri Sep 24, 2021 6:36 am
Re: q=mCΔT vs q=nCΔT
It's the same equation but varies depending on the units. Use q=nCΔT if in mols and use q=mCΔT if the mass is in grams.
-
- Posts: 104
- Joined: Fri Sep 24, 2021 5:07 am
Re: q=mCΔT vs q=nCΔT
Yes, these equations mean the same thing, q is the same value no matter if we use q=mcdeltaT or q=nCdeltaT to calculate it for a sample. However, the C values that are used in these equations is different. In the first equation C is in Jg^-1K^-1 and in the second equation it is in Jmol^-1K^1. m is mass (g) and n is moles (mol).
-
- Posts: 99
- Joined: Fri Sep 24, 2021 6:07 am
-
- Posts: 101
- Joined: Fri Sep 24, 2021 6:57 am
Re: q=mCΔT vs q=nCΔT
You can use them based on the units given. You would use q=mCΔT if you are given the mass in grams and you would use q=nCΔT if you are given the moles.
Re: q=mCΔT vs q=nCΔT
It depends if you are using the in the heat capacity for one gram or for one mole. As long as you make sure your units cancel you will be good to go.
-
- Posts: 100
- Joined: Fri Sep 24, 2021 7:11 am
Re: q=mCΔT vs q=nCΔT
When you are given the specific heat capacity, you don't have to convert grams to moles and you can use grams such as in mCΔT. When you are given the molar specific heat capacity, you convert grams to moles and use nCΔT.
-
- Posts: 102
- Joined: Fri Sep 24, 2021 7:15 am
Re: q=mCΔT vs q=nCΔT
Hi! If you were given the mass you can use q=mCΔT and if you were given moles you can use q=nCΔT.
-
- Posts: 100
- Joined: Fri Sep 24, 2021 5:34 am
Re: q=mCΔT vs q=nCΔT
Yes! Just depends on what you are given for the mass. If its in moles then use q=ncdT and if its in grams them use q=mcdT
Re: q=mCΔT vs q=nCΔT
If the equation is giving us mols we use q=nCΔT and if we are given the mass in grams we use q=mCΔT. The key is to pay attention to the units from what the problem gives us.
-
- Posts: 100
- Joined: Wed Feb 17, 2021 12:23 am
Re: q=mCΔT vs q=nCΔT
q=mCΔT can be used when the heat capacity given is in mass (per gram) and q=nCΔT can be used when the heat capacity given is per mol.
-
- Posts: 107
- Joined: Fri Sep 24, 2021 6:32 am
Re: q=mCΔT vs q=nCΔT
Yeah you can definitely use these interchangeably. When you're given C in moles you use the equation with n and when you get it in grams you use it with m. Hope this helps!
-
- Posts: 101
- Joined: Fri Sep 24, 2021 5:42 am
Re: q=mCΔT vs q=nCΔT
Not always. There is a difference between C and c. C is a more broad heat capacity, whereas c is a subcategory of heat capacity, known as specific heat. In the end, they work as more or less of the same thing, so I guess that they are interchangeable, in a sense.
-
- Posts: 50
- Joined: Wed Nov 11, 2020 12:18 am
Re: q=mCΔT vs q=nCΔT
We would use q=mCdeltaT when we have the specific heat capacity/ moles and would use q=nCdeltaT when we have the molar capacity/moles. SO we would use either based on what we are given.
-
- Posts: 37
- Joined: Mon Jan 09, 2023 10:06 am
- Been upvoted: 1 time
Re: q=mCΔT vs q=nCΔT
Thank you very much, I appreciate the help. I always thought that you had to convert the grams to moles. I finally know that you can interchange the equation.
-
- Posts: 35
- Joined: Mon Jan 09, 2023 2:28 am
Re: q=mCΔT vs q=nCΔT
Hi! They are essentially the same it just depends on the units you need to use. q=mCdeltaT is for specific heat capacity/ moles whereas q=nCdeltaT is for molar capacity/ moles.
-
- Posts: 35
- Joined: Mon Jan 09, 2023 2:39 am
Re: q=mCΔT vs q=nCΔT
I think many people have adequately responded to this question, one thing to keep in mind is what is given. As professor Lavelle says "Dont change the Chemistry!" So if we are given something in kJ/(mol * K) we know we must multiply it by moles, so if we are given the grams of a substance, we must take an extra step and calculate the number of moles using the molar mass. Hope that helps!
-
- Posts: 35
- Joined: Mon Jan 09, 2023 2:30 am
Re: q=mCΔT vs q=nCΔT
Both equations will give you the same answer in kJ or J. The difference is simply in the units. If given the specific heat capacity, utilize the q=mCΔT equation. If given the molar heat capacity, utilize the q=nCΔT equation
-
- Posts: 38
- Joined: Mon Jan 09, 2023 9:30 am
Re: q=mCΔT vs q=nCΔT
The two equations are essentially the same, but the key difference lies in the units of the parameters. If the heat capacity is given in units with grams, then the equation with the mass can be used. If the heat capacity is given in terms of moles, the the equation with the moles can be used.
-
- Posts: 34
- Joined: Mon Jan 09, 2023 9:02 am
Re: q=mCΔT vs q=nCΔT
Both equations q=mCdeltaT and q=nCdeltaT are basically the same aside from the units that are used which is a big difference. The q=mCdeltaT equation is used for specific heat capacity while q=nCdeltaT is used for molar heat capacity.
-
- Posts: 34
- Joined: Mon Jan 09, 2023 8:24 am
Re: q=mCΔT vs q=nCΔT
Hello,
These equations can be used interchangeably as long as you have the correct unit, either moles or grams depending on the equation. However it is important to focus on the heat capacity given.
q= m deltaC T is used for mass and specific heat capacity
q= n C deltaT is used for moles and molar heat capacity
These equations can be used interchangeably as long as you have the correct unit, either moles or grams depending on the equation. However it is important to focus on the heat capacity given.
q= m deltaC T is used for mass and specific heat capacity
q= n C deltaT is used for moles and molar heat capacity
-
- Posts: 41
- Joined: Mon Jan 09, 2023 8:34 am
Re: q=mCΔT vs q=nCΔT
Yes, these two equations can be used interchangeably. However, it's important to note whether the heat capacity C is given in units of per gram or per mole. As long as the units for both match, you are free to use the equations depending on what information you have available to you in the problem.
-
- Posts: 34
- Joined: Mon Jan 09, 2023 9:27 am
Re: q=mCΔT vs q=nCΔT
q=mCΔT can be used for when C has the units of J/gK (or J/gC) when you are using grams for the m. On the other hand, q=nCΔT can be used for when C has the units of J/molK ( or J/molC) when using moles for n.
Re: q=mCΔT vs q=nCΔT
Yes. You can just use q=mCdeltaT when given grams and q=nCdeltaT when given moles. You can convert depending on the specified units they are asking for in the answer.
Return to “Concepts & Calculations Using First Law of Thermodynamics”
Who is online
Users browsing this forum: No registered users and 6 guests