Law of Dulong and Petit?

Question

Bronze is an alloy of tin (MM 118.7) and copper (MM 63.55). If a 105.0 gram block of a bronze alloy has a heat capacity of 28.4 J/K, calculate the mole fraction of copper in the alloy. The Dulong-Petit constant = 24.94 J/K.mol. Enter your answer as a number with three significant figures.

Answer 1

1.1387 mol weigh 105 g

1 mol weighs = 92.21 g

So, 118.7 x + 63.55 (1-x) = 92.21

% age of Sn = 51.97 %

Of Cu = 48.03 %