Name _________________________________
UNIT 4 – PURE SUBSTANCES AND MIXTURES
(DEMONSTRATIONS & NOTES)
A. Physical and Chemical Properties: ALL substances and mixtures have a list of physical and chemical properties.
Here is a small table of some of these properties for water and ethanol (or ethyl alcohol).
Next to the words physical and chemical properties write a good working definition for each.
Property
Water
Ethanol
Physical properties:
Appearance/color
None
None
Density
1.0 g/mL
0.79 g/mL
M.p./f.p.
0 oC
-117oC
o
B.p./c.p.
100 C
80oC
Odor
None
Noticeable
Magnetism
No
No
Electric conductivity
Solubility of sugar
Chemical properties:
flammability
Not flammable
Very flammable
B.
B. Demonstrations: Put PARTICLE DIAGRAMS in the BOXES and
UNDER each box write EITHER:
PURE SUBSTANCE-ELEMENT, PURE SUBSTANCE-COMPOUND OR MIXTURE.
1. Water, ethanol and sugar:
Water
________________
Ethanol
________________
Water & Ethanol
Water & Sugar
_______________ ________________
Ethanol & Sugar
_________________
Water, Ethanol & Sugar
_________________
Which boxes did you identify as mixtures? ___________________________________________________________
How did you determine that they were mixtures? _____________________________________________________
How can you separate ethanol & water? What is that process called? _____________________________________
What physical property does that separation method use? _______________________________________
Draw a diagram of the whole apparatus:
2. Sand, Salt & Sugar:
Sand (SiO2)
Salt (NaCl)
Sugar
Sand, Salt & Sugar
_________________ ________________ _________________
________________
Which one of these items did you determine as pure substances? Why?
______________________________________________________________________________________________
How can you separate out the sand, salt and sugar so that each of these 3 things end up in separate containers?
______________________________________________________________________________________________
______________________________________________________________________________________________
What physical properties would you use?
______________________________________________________________________________________________
3. Sulfur and Iron:
Sulfur (S)
__________________
Iron (Fe)
_____________________
Sulfur + Iron (without heating)
___________________
Sulfur + Iron (after heating)
____________________
Did you determine the sulfur and iron (separately) a pure substance or a mixture? Why?
______________________________________________________________________________________________
When the sulfur and iron were mixed without heating, was a pure substance or mixture created? How can you tell?
______________________________________________________________________________________________
How can you separate the sulfur and iron (without heating one)? What physical property did you use?
______________________________________________________________________________________________
What happened after the sulfur and iron were heated together? What was formed, a pure substance or mixture?
How did you know?
______________________________________________________________________________________________
______________________________________________________________________________________________
Can you separate the sulfur and iron easily after they were heated together? ______________________________
What happened to all the physical and chemical properties of the sulfur and iron after they were heated together?
______________________________________________________________________________________________