Hydrate Lab Makeup Assignment: Formula of a Hydrate
Name ___________________________ Class ________ Teacher__________________________
Part A: Answer the following questions in full sentences.
1. What is meant by a hydrate.
2. Why is the formula of the water in a hydrated compound separated by a dot (e.g. BaCl2•2H2O) instead of
being included in one formula (BaCl2H4O2)?
3. Why is the hydrate heated during the experiment?
Part B: Use this sample data to answer the questions below.
Show all your calculations.
Observations:
Mass of empty crucible and cover = 24.32 g
Mass of apparatus and hydrate = 26.75 g
Mass of apparatus and salt after heating = 25.88 g
------------------------------------------------------------------------------------------------------------------------------------Analysis:
Mass of hydrate =
Mass of water =
Mass of dehydrated salt =
Calculations:
1. Calculate the percent composition of water for this hydrate.
2. Determine the molecular formula (the value of x) for the hydrate.
CuSO4•xH2O
3. Two possible sources of error can occur in this experiment.
i. The hydrate might not be heated for a long enough period of time.
ii. The hydrate is heated for an over extended amount of time.
State and explain how each would have altered the correct value for x in the reported formula.