How Do You Determine Heat Capacity for Liquids?

[Joseph Rolls]

Homework Statement

By consulting the literature, find the heat capacity for the liquids in the table at the approximate mid-point in temperature for the liquid phase. (table given in 'attempt at a solution' below)

Relevant Equations

for einstein solid: Cv=Nk
for ideal gas: Cv=fNk/2

liquid	melting point (degrees C)	boiling point (degrees C)
water (H2O)	0	100
sodium (Na)	98	883
Sodium-potassium(NaK)	-11	785
Lead(Pb)	327	1749

I'm prettttty sure by consulting the literature means by using the above table… but if that's the case then how in the world do you find Cv for a liquid. I thought maybe we could use the formulas to find Cv for a solid and gas and the Cv for liquid might be halfway between… but for water Cv is approx 2000 for solid, 4000 for liquid and 2000 for gas so that idea is certainly wrong.

Is there an equation to find C for a liquid?? or am i just supposed to go online and find some literature that tells me what the heat capacity is for each liquid… this question is worth 30 marks so i figured it couldn't be so simple as googling the answer.

 

[trurle]

liquid	melting point (degrees C)	boiling point (degrees C)
water (H2O)	0	100
sodium (Na)	98	883
Sodium-potassium(NaK)	-11	785
Lead(Pb)	327	1749

I'm prettttty sure by consulting the literature means by using the above table… but if that's the case then how in the world do you find Cv for a liquid. I thought maybe we could use the formulas to find Cv for a solid and gas and the Cv for liquid might be halfway between… but for water Cv is approx 2000 for solid, 4000 for liquid and 2000 for gas so that idea is certainly wrong.

Is there an equation to find C for a liquid?? or am i just supposed to go online and find some literature that tells me what the heat capacity is for each liquid… this question is worth 30 marks so i figured it couldn't be so simple as googling the answer.

Water have rather anomalous thermal capacity of liquid, therefore make a poor reference.
Most other materials (including sodium) have thermal capacity which do not have discontinuity at melting point.
https://nvlpubs.nist.gov/nistpubs/jres/045/jresv45n1p23_A1b.pdf

 

[Chestermiller]

Look it up online.