Question

A hydrate of CoCl2 has a mass of 17.40 g before heating. After heating, the mass of the anhydrous compound is found to be 10.27 g. Explain how you would determine the formula of the hydrate and then write out the full name of the hydrate.

Answer 1

Mass CoCl2 = 10.27 g
moles CoCl2 = 10.27 g/ 129.839 g/mol=0.07910

mass water = 17.40 - 10.27=7.13 g
moles water = 7.13 / 18.02 g/mol=0.396

0.396/ 0.07910=5

CoCl2 * 5 H2O

moles CaF2 = 85.8 g/ 78.0748 g/mol=1.10
moles Ca = 1.10
mass Ca = 1.10 x 40.078 g/mol=44.1 g
V = 44.1 / 1.55 =28.5 mL

Greetings!!