Purpose: The purpose of this lab is to: 1: practice the scientific method by observing chemical reactions
2: practice creating controlled experiments.
Materials:
Chemicals
 Calcium chloride, CaCl2
 Sodium Bicarbonate, NAHCO3
***Safety***-body irritant, slightly toxic if ingested.
 Phenol red solution
 Water, H2O
Lab equipment
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Plastic zip lock bags
Goggles ****
Watch glasses, 2
Weight Scale/ Electric Scale
Beaker, 30ml 2
Graduated cylinder, 10ml 2
Pipets
Spatula or teaspoon
Procedure:
Part1:
1. Using a scale and watch glass weigh 3.5g of calcium chloride. Record any
observations about this chemical in your 1.1 data table (color, shape, smell etc…)
2. Weight 1.75g of sodium bicarbonate. Record any observations in 1.1 data table.
3. Using a pipet, measure 3ml of phenol red and pour it into a 10ml graduated cylinder.
Record any observations in 1.1 data table.
4. Using a pipet measure 3ml of water and pour it into a 10ml graduated cylinder.
Record any observations in 1.1 data table.
5. Place both calcium chloride and sodium bicarbonate in LEFT side of the bag.
6. Pour the two liquids into the other side of the bag being careful not to mix with the
solids (squeeze solid side so liquid can’t enter)
7. Try and squeeze the air out of the bag before sealing it.
8. Mix the contents of the bag well.
9. Make observations about the changes that take place inside the bag. Look for
changes in color, temperature, amount of air in the bag, and any other observations.
Record observations in your 1.1 data table
1.1 Data Table
Physical Properties
Reagent (chemical)
Observations
Calcium Chloride (CaCl2)
Sodium Bicarbonate (NaHCO3)
Phenol Red
Water (H20)
Initial Reaction
CaCl2, NaHCO3, Phenol Red, H20
Questions:
1. Name the four variables in the reaction
2. Design 5 experiments to determine which reactants caused the observable results in the
first experiment. These will help you answer part 2 questions (write the chemicals you will
use)
Experiment 1:
Experiment 2:
Experiment 3:
Experiment 4:
Experiment 5:
Part 2
1. Using the same procedure as part one tests your 5 experiments. (
Controlled Experiments
Reactants
Control Experiment 1
Control Experiment 2
Control Experiment 3
Control Experiment 4
Control Experiment 5
Observation
Questions and Analysis- Based on your controlled experiments answer these questions.
1. Which reactants were responsible for the color change? Explain how you know. /2
2. Which reactants were responsible for the temperature increase? Explain how
you know.
3. Which reactants were responsible for creating gas? Explain how you know /2
/2