Chemical and Physical Changes
Physical Change – change in appearance such as size, shape, state (solid, liquid, gas)
Chemical Change – new substance is formed
4 Indications a Chemical Reaction may have taken place:
 Energy Change – Heat or Light
o Endothermic – energy absorbed
o Exothermic – energy released
 Color Change
 Fizzing or bubbling – evolution of a gas
 Formation of a solid – precipitate
Purpose: Observe the reaction between solid aluminum and a solution of Copper (II) Chloride.
Procedure:
1. Place a 0.80g to 1.00g sample of copper(II)Chloride in a large test tube
2. Add 3.0 ml of water
3. Stir the solution
4. Record the temperature of the solution
5. Obtain a piece of aluminum foil 2.0cm by 6.0cm
6. Roll the Al foil around a pen or stirring rod to form a loose cylinder
7. WITH SAFETY GLASSES ON, drop the Al cylinder into the test tube
8. Record observation and record the temperature once the reaction has ceased
9. Filter the contents of the test tube
10. Record the phase and color of each product
Data:
Substance
Reactant or
Product
Physical
properties
Soluble in water?
Formula
Aluminum
Copper (II)
Chloride
Copper
Aluminum
Chloride solution
Observations:
Word Equation:
Solid Aluminum reacted with a solution of copper (II) chloride to form solid copper and a solution
of aluminum chloride plus heat energy.
___ Al (s) + ___
CuCl2 (aq)  ___ Cu (s) + ___ AlCl3 (aq) + energ
Conclusions and Questions:
1. Is Copper (II) Chloride soluble in water? ______________
2. Is aluminum a metal or a nonmetal? _______________
3.
Atomic
#
13
17
29
Name
Metal/nonmetal
Symbol
4. Identify the following as either physical or chemical change:
Tearing Al foil
Dissolving CuCl2
Decomposing water into hydrogen and oxygen
The disappearance of solid air freshener (
Boiling water (
)
Melting wax (
)
Burning wax
Reacting Al foil with CuCl2
Freezing water (
)
)
5. When writing the formula for a compound, the little numbers written in the formula are called
_____________________
6. When writing an equations, the lines in front will be used to write the numbers called the
______________________________
7. Describe the contents of the beaker after the reaction has stopped. What color is the solution,
what color is the solid? ____________________________
8. Are any of the reactants still present in the beaker? If yes, which one(s)?
___________________________________________________________
9. Why did the reaction stop?
10. was the reaction endothermic or exothermic and why?
____________________________________________________________________________
Cleanup:
Pour off the solution(into the drain) without allowing any of the solid to escape. Scrap the solid
into the trash can.