Heat Capacity: Units, Mols & Avogadro's Constant

In summary, the conversation is discussing the equation for heat capacity for constant volume and pressure, which is Cv = Cp - R. The units for Cp are J/k, and for R they are J/k mol. The question is whether the mol should be eliminated, and if so, if Avogadro's Constant is involved. It is then mentioned that the correct units for Cp are kJ/kgK, which can be rewritten as kJ/kmol*K. The difference between the gas constant and universal gas constant is also mentioned. Finally, the conversation talks about the use of the equation Cp = Q/dT, and an example where Cp is calculated to be 50 J/K.
  • #1
jimmy42
51
0
I have the equation for heat capacity for constant volume and pressure.

Cv = Cp -R

So for Cp I have the units J/k and for R the units are J/k mol. So my question is related to that mol. Is it right that I need to get rid of that mol? if so how? Does it involve Avogadro's Constant? Or do I have the wrong units for Cp?

Thanks.
 
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  • #2
The units for cp is kJ/kgK which can be rewritten as kJ/kmol*k. Although I know that R to be the gas constant and not the universal gas constant.
 
  • #3
I have

Where Q is the energy as heat and dT is the change in temp in Kelvin.

Cp = Q/dT

Cp = 100J / 2K

Cp = 50 J/K

So, is that not right? R = molar gas constant.
 

1. What is heat capacity?

Heat capacity is the amount of energy required to raise the temperature of a substance by one degree Celsius.

2. What are the units of heat capacity?

The units of heat capacity are joules per degree Celsius (J/°C) or calories per degree Celsius (cal/°C).

3. How is heat capacity measured?

Heat capacity is measured by heating a known mass of a substance and measuring the change in temperature.

4. What is the relationship between heat capacity and molar heat capacity?

Molar heat capacity is the heat capacity per mole of a substance. It is directly proportional to the heat capacity and is dependent on the number of moles of a substance rather than its mass.

5. What is Avogadro's constant and how is it related to heat capacity?

Avogadro's constant is a number that represents the number of particles in one mole of a substance. It is related to heat capacity through the molar heat capacity, as the heat capacity of a substance is directly proportional to the number of particles present.

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