Name ____________________________________________________________ Date __________________
The Mole
Section 5 Formulas of Hydrates
Skim Section 5 of your text. Write three questions that come to mind from
reading the headings and the illustration captions.
1. ____________________________________________________________
2. ____________________________________________________________
3. ____________________________________________________________
Use your text to define the following term.
hydrate
_______________________________________________________________
_______________________________________________________________
Naming Hydrates
Explain how hydrates are named by completing the table below.
.
Prefix Molecules
of Water
mono-
1
2
3
4
5
6
7
8
nona-
9
10
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Name ____________________________________________________________ Date __________________
Section 5 Formulas of Hydrates (continued)
Analyzing a
Hydrate
Describe an anyhydrate.
_______________________________________________________________
_______________________________________________________________
Determining the
Formula of a
Hydrate
Use with Example
Problem 14
Solve Read Example Problem 14 in your text.
You Try It
Problem
A 5.00 g sample of barium chloride hydrate was heated in a crucible. After
the experiment, the mass of the solid weighed 4.26 g. Determine the
number of moles of water that must be attached to BaCl2.
1. Analyze the Problem
Known:
mass of hydrated compound _____ g BaCl2  x H2O
mass of anhydrous compound  _____ g BaCl2
molar mass of H2O ______ g/mol
molar mass of BaCl2  208.23 g/mol
Unknown:
formula for hydrate
name of hydrate
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Name ____________________________________________________________ Date __________________
Section 5 Formulas of Hydrates (continued)
2. Solve for the Unknown
Subtract the mass of the anhydrous compound from the hydrated
compound.
__________________________________________________________
Calculate the number of moles of H2O and anhydrous BaCl2 using the
conversion factor that relates moles and mass based on the molar mass.
1mol BaCl2
4.26 g BaCl2 x
 ____________________
208.23 g BaCl2
0.74 g H2O x
1mol H2O
 ___________________
18.02 H2O
Determine the value of x.
x
0.0411mol H2O
moles H2O


moles BaCl2 0.0205 mol BaCl2
2
3. Evaluate the Answer
The ratio of H2O to BaCl2 is _______ so the formula for the hydrate is
____________, and the name of the hydrate is _________
________________.
REAL-WORLD CONNECTION
Explain why hydrates are useful in storage and shipping.
_________________________________________________________________________________________
_________________________________________________________________________________________
_________________________________________________________________________________________
Chemistry: Matter and Change
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Science Notebook
Chemistry: Matter and Change
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Science Notebook