1. M EASUREMENTS AND C ALCULATIONS IN CHEMISTRY - HYDRATES Dr. Chin Chu Chemistry River Dell High School

2. D EFINITION : Hydrates in Inorganic Chemistry – are inorganic salts “containing water molecules combined in a definite ratio as an integral part of the salt crystal that are either bound to a metal center or that have crystallized with the metal complex.

3. N AMING OF H YDRATES

4. N AMING OF H YDRATES – E XERCISE FormulaName CoBr 2 · 6H 2 O ZnSO 4 · 7H 2 O Copper(II) nitrate monohydrate Iron(III) nitrate nonahydrate

5. N AMING OF H YDRATES – E XERCISE A NSWERS FormulaName CoBr 2 · 6H 2 O Cobalt(II) bromide hexahydrate Cu(NO 3 ) 2 · H 2 O ZnSO 4 · 7H 2 O Fe(NO 3 ) 3 · 9H 2 O Copper(II) nitrate monohydrate Zinc sulfate heptahydrate Iron(III) nitrate nonahydrate

6. H OW TO FIGURE OUT THE HYDRATE FORMULA ?

7. T HE PROCESS

8. H YDRATES E XAMPLE A calcium chloride hydrate has a mass of 4.72 g. After heating for several minutes the mass of the anhydrate is found to be 3.56 g. Use this information to determine the formula for the hydrate.

9. A hydrate of magnesium sulfate has a mass of 13.52 g. This sample is heated until no water remains. The MgSO 4 anhydrate has a mass of 6.60 g. Find the formula and name of the hydrate. When 8.00 g of Pb(C 2 H 3 O 2 ) 2 · x H 2 O are heated, 1.14 g of H 2 O are driven off. Find the chemical formula and the name of the hydrate. A hydrate is determined to be 45.43% water and 54.57% CoCl 2. Find the chemical formula and name for this hydrate. (*Hint – assume that there is 100 g total of hydrate compound.) HYDRATES – PRACTICE PROBLEMS

10. [MgSO 4 ·7H 2 O, magnesium heptahydrate] [Pb(C 2 H 3 O 2 ) 2 · 3H 2 O, lead(II) acetate trihydrate] [CoCl 2 · 6H 2 O, cobalt(II) chloride hexahydrate] HYDRATES – PRACTICE PROBLEMS A NSWERS