CHEM 106; Chemical Separations – Elements, Compounds, and Mixtures
Pre-lab preparation: Define the following terms in your own words
Matter
Pure Substance
Element

Matter-

Physical Property-

Chemical Property-

Pure Substance-

Element -

Compound -

Homogeneous Mixture -

Heterogeneous Mixture –
Compound
Mixture
Homogeneous
Mixture
(solution)
Heterogeneous
Mixture

Lab work often involves separating mixtures into its component parts. Below is a diagram of six methods. Beside
of each method write a BRIEF summary of the process.
Filtration
Evaporation
Solubility
Extraction
Methods
used to
physically
separate
mixtures
Fractional
Crystallization
Decantation
Distillation

Which method will you use in the lab experiment?
Purpose: You will see some of the differences between elements, compounds, and mixtures. You will also learn several
methods used to separate one species from another in the laboratory and utilize these methods to determine the
components of an unknown mixture.
Safety notes: You are required to use goggles – you will be using 6M hydrochloric acid.
Hypothesis: What do you think will be the differences between elements, compounds, and mixtures in their properties?
(This lab will not require an if…then statement. After completing the lab you will predict the identity of an unknown
substance based on properties you test during the experiment.)_
Materials: Read through the experiment and create a complete list of materials for Part II– pretend this is “Chemistry
for Dummies.”
Procedure: see packet – read carefully.
Observations:
Part I - 1. Complete the table:
Element
Iron
Sulfur
Magnesium
Physical State
Color
Luster
2.
a. Describe the appearance of the mixture of iron and
sulfur.
b. What effect did the bar magnet have on this mixture?
3.
a. Describe the appearance of the compound, FeS.
b. What effect did the bar magnet have on this compound?
Part II. A Study of a Mixture and its Separation
1.
Indicate the solubility behavior of each substance in water and 6M HCl. Indicate as soluble (S) or insoluble (I).
Basically do they dissolve or not.
Sand
Powdered magnesium
Sodium chloride
water
6 M HCl
Unknown mixture number:
2.
Components of the Mixture:
a. Observation upon evaporation
of the water filtrate.
b. Observations upon adding 6 M
HCl to the residue on the filter
paper.
Conclusion: List the components present in your unknown mixture – defend with your observations – Why do you think
those components are correct?
/28
Prelab definitions & separation techniques
/5
Clear and Appropriate HYPOTHESIS.
/15
Complete list of MATERIALS
/22
Accuracy of DATA
/20
Accurate CONCLUSIONS with appropriate defense.
/10
Lab Safety- No group members were cited for safety violations. Lab equipment was returned
and lab area cleaned properly.
_______
--------Total points earned = Lab grade-------->
Bonus: (5 points)
How could you improve your results, if you were given the opportunity to revise this experiment?