If you look at the table of specific heat values for different metals, they are

Question

If you look at the table of specific heat values for different metals, they are all so different from one another. The difference is mainly because specific heat is expressed as energy per unit mass. If specific heat were given as energy per mole, the values would be very similar. It is, in fact, this similarity of the molar specific heats of metals, which is the basis for the Law of Dulong and Petit. The law of Dulong and Petit states that the heat capacity of a metal in J/g oC multiplied by the molar mass of the metal in grams/mole is a constant:

Cp x Molar Mass = 25 J/moloC

Using the heat capacity value of 0.3854J/moloC , solve for the molar mass of the metal. (Put your answer in 4 significant figures)

Based on your calculations, which metal is this?

Explanation / Answer

Molar heat capacity = Cp * Molar mass

25 J / moloC = 0.3854 J / moloC * Molar mass

Molar mass = 25 / 0.3854 = 64.8677 amu

This molar mass is approximately equal to that of copper ( 63.546 +/- 0.003 amu). So the metal is Copper.

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