The molal freezing point constant for copper is 23 °C/m. If pure copper melts at 1083°C, what will be the melting point of a brass made of 13.4 mass percent Zn and the remainder Cu?

The freezing point of brass is 1028.57°C

Explanation:

We are given:

13.4 mass percent of zinc in brass

This means that 13.4 grams of zinc is present in 100 g of brass

Mass of copper = [100 - 13.4] g = 86.6 g

Depression in freezing point is defined as the difference in the freezing point of pure solution and freezing point of solution.

The equation used to calculate depression in freezing point follows:

To calculate the depression in freezing point, we use the equation:

Or,

where,

Freezing point of pure copper = 1083°C

i = Vant hoff factor = 1 (For non-electrolytes)

= molal freezing point elevation constant = 23°C/m

= Given mass of solute (zinc) = 13.4 g

= Molar mass of solute (zinc) = 65.38  g/mol

= Mass of solvent (copper) = 86.6 g

Putting values in above equation, we get:

Hence, the freezing point of brass is 1028.57°C

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.