Chemistry
Lab 1
Title: Qualitative Observations of a Chemical Reaction (Candle
Lab)
Objective: Observation and interpret a simple chemical reaction
Materials: Candle, Matches, aluminum foil, limewater, and cobalt
chloride paper.
Equipment: 250mL Beaker, 125mL Erlenmeyer flask, rubber
stopper, and Glass Square
Procedure:
1. Using your senses describe the unlighted candle and record
observations.
2. Secure candle to the base of glass square (teacher will
demonstrate).
3. Light candle, allow it to burn for a minute and record your
observations.
4. Blow out the flame and immediately place a lighted match in
the smoke about 2 cm above the wick and record
observation.
5. Make a slit in a small piece of aluminum foil. Light the
candle. Place the foil between the base of the flame and the
liquid in the candle bowl. Record observation.
6. Invert 250 beaker over the flame. Record observation. Test
the collected residue with cobalt chloride paper.
7. Invert 125 Erlenmeyer flask over the flame for several
minutes. Remove flask, turn it right side up, and add about
10 mL of limewater solution. Record observation.
Analysis questions
1. Which phases are present in the unlighted candle? Which
phases are present in the burning candle?
2. Which phases take place in the chemical reaction?
3. What is the purpose of the wick? How did the foil interfere
with chemical reaction?
4. What two substances are indicated by the cobalt and
limewater tests? Explain why it is possible for other
substances produced during the chemical reaction?
5. What type of reaction was taken place? Endothermic or
Exothermic
6. What is the difference between observation and
interpretation? Give an example.