Question

A student performed the Fractional Crystallization experiment described with the following results: Initial mass of sample mixture: 4.958 g, mass of salicylic acid recovered, 0.586 g; mass of CuSO4•5H2O recovered, 3.12 g. The recovered CuSO4•5H2O was then heated for 15 minutes at 130 °C. The mass of the new hydrate was 2.17 g. Calculate the value of X in the formula for the new hydrate CuSO4•XH2O.

Answer 1

74.75%

Step-by-step explanation:

To calculate this, we simply add the mass of the salicylic acid and the mass of the copper sulphate.

The addition will yield the following.

Mass of salicylic acid recovered = 0.586g

Mass of copper sulphate recovered = 3.12g

The addition of both is = 0.586g + 3.12g = 3.706g

The percentage composition can be calculated by dividing this by the original mass of the mixture before crystallization and dividing by 100.

3.706/4.958 * 100 = 74.75%