Cobalt chloride can be prepared in the laboratory by the following chemical equa
ID: 554629 • Letter: C
Question
Cobalt chloride can be prepared in the laboratory by the following chemical equation:
Co(s) + HCl(l) H2 (g) + "cobalt chloride"
Use the following information to determine formula of the cobalt chloride that is formed. (do not determine by balancing the equation)
When 0.4878 g of cobalt solid is heated with an excess of hydrochloric acid (HCl), 1.368 g of cobalt
chloride is produced. Do your best to show your work.
Hints: Hydrochloric acid serves as the source of chlorine for the resultant compound, and the mass of cobalt is completely incorporated into the cobalt chloride product.
Explanation / Answer
Mass of cobalt taken = 0.4878 g
mass of cobalt chloride formed = 1.368 g
Thus mass of chlorine in the product = 1.368 -0.4878
= 0.8802 g
Element cobalt chlorine
mass 0.4878 0.8802
atomic mass 58.93 35.5
moles of atoms 0.4878/58.93 0.8802/35.5
=0.008277 = 0.02474
ratio of moles 0.008277/0.008277 0.02474/0.08277
= 1 = 2.98
Thus the formula of cobalt chloride formed is
Co1 Cl3 or CoCl3