Lab 2

Objectives
Differentiate between physical and chemical changes.
Make measurements using various types of lab equipment.
Compare density to viscosity.

Procedure
Lab teams will travel to six stations. At each station is a task to be performed by the lab team. Follow the instructions at each station and record your findings. Each team member will assume one of four roles – materials manager, facilitator, timer and recorder during this lab. All safety precautions should be taken to prevent any exposures to hazards.

Station 1 Density
Using the scale provided, weigh each bar of soap (mass). Using its dimensions (l x b x h), calculate its volume. Determine the density of each bar of soap. (D=m/v)

Question
What is different about the two bars of soap? Which bar of soap is a better value?

Station 2 Viscosity
Rank the substances by viscosity.
__ oil
__ water
__ honey
___ hair gel

Explain your choices.

Station 3
Crush the sample tablet. Place the pieces in the film canister. Add a little bit of water and quickly close the canister and turn it upside down. Step back from the canister and observe the reaction. Make sure you do not point the canister at any person. Goggles are needed during this experiment.

Question
Is this a chemical or physical change?

Station 4
Grab a handle of detergent. Do not let go. Dip your entire hand in the water bucket. Note the feeling in your hand and record your observations.

Question
What did you feel in your hand? Is this a chemical or physical change?

Station 5
Light a candle. Notice what is happening to the wax and record your observations.

Question
Is this a chemical or physical change?

Station 6

Place a small amount of sugar in the dish. Drop several drops of sulfuric acid to the sugar. Note the reaction and record your observations.

Question
Is this is chemical or physical change?