Finding heat capacity for liquids

In summary, the conversation discusses the thermal properties of different liquids and the difficulty in finding their specific heat capacity (Cv). The conversation mentions the values for melting and boiling points, and how they differ for each liquid. The questioner is unsure how to find the Cv for a liquid, but the answer suggests looking it up online. It is noted that water has an unusual thermal capacity compared to other materials, making it not a good reference for finding Cv.
  • #1
Joseph Rolls
9
5
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
liquidmelting point (degrees C)boiling point (degrees C)
water (H2O)0100
sodium (Na)98883
Sodium-potassium(NaK)-11785
Lead(Pb)3271749

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.
 
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  • #2
Joseph Rolls said:
liquidmelting point (degrees C)boiling point (degrees C)
water (H2O)0100
sodium (Na)98883
Sodium-potassium(NaK)-11785
Lead(Pb)3271749

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
 
  • #3
Look it up online.
 

What is heat capacity and why is it important in studying liquids?

Heat capacity is the amount of heat required to raise the temperature of a substance by one degree. It is an important factor in studying liquids because it helps us understand how much energy is needed to change the temperature of a liquid, which can have practical applications in various industries such as energy production and chemical reactions.

How do you measure heat capacity for liquids?

Heat capacity for liquids can be measured using a calorimeter, which is a device that measures the heat exchange between a sample of liquid and its surroundings. The liquid is heated or cooled and the change in temperature is recorded, along with the amount of energy used to cause the temperature change. The heat capacity can then be calculated using this data.

What factors can affect the heat capacity of a liquid?

The heat capacity of a liquid can be affected by several factors, including the type of liquid, its temperature, and its molecular structure. Other external factors such as pressure, impurities, and the presence of other substances can also influence the heat capacity of a liquid.

Why is it important to find the heat capacity for different liquids?

Finding the heat capacity for different liquids can help us understand their thermal properties and how they respond to changes in temperature. This information can be useful in various industries, such as designing heating and cooling systems, determining the energy needed for chemical reactions, and understanding the behavior of liquids in different environments.

Can heat capacity be changed or controlled?

Heat capacity is an intrinsic property of a substance and cannot be changed or controlled. However, external factors such as pressure, temperature, and the presence of other substances can affect the heat capacity of a liquid. By controlling these factors, we can indirectly influence the heat capacity of a liquid.

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