Observing Change
1. In a sealable pastic bag,
3. Squeeze out any excess air from the bag, and then seal it.
4. Tip over the bag so that the water spills out of the cup and mixes with the calcium chloride and baking soda
5. Record your observations.
What evidence of a chemical reaction did you observe?
Mostly Cloudy
1. Put on your safety goggles
2, Pour about 5 mL of limewater (lime from the gardening store) into a plastic cup
3. Pour an equal amount of plain water into another plastic cup
4. Add about 5 mL of carbonated water to each of the cups
Drawing Conclusions
1. In which cup do you think a chemical reaction occurred?
2. What evidence supports your conclusion?
Getting Warmer
Materials
small beaker
dry yeast in a plastic cup
3% hydrogen peroxide ( what you get at the store)
in the glass beaker
spoon
Procedure
1. Put your hand on the outside of
the beaker and notice how cool or warm it is.
2. In your beaker of peroxide stir in yeast with
a spoon.
3. Observe what happens over a period of time
and record.
4. Feel the lower sides and bottom of the beaker.
Record your findings.
Analysis and Conclusions
1. What evidences did you observe that supports
there was a chemical reaction?
2. Based on your observations, what do
you think was being produced when the hydrogen peroxide and yeast were
mixed ? Explain why your came up with your answer.
Adapted from 365 Simple Science Experiments
by E. Richard Churchill, Louis V. Loeschnig, and Muriel Mandell
Brrr! It's Cold
Materials
room temperature water
plastic cup of Epsom salts (magnesium sulfate)
spoon
medium sized glass beaker (needs to be glass)
Procedure
1. Fill the jar or beaker with room temperature
water about 1/2 full.
2. Put your hand on the outside of the beaker
and notice how cool or warm it is.
3. Record your observation.
4. Stir in the Epsom salts.
5. Feel the beaker again. Record your observations.
Analysis and Conclusions
1. Does mixing Epsom salts and water
represent physical or chemical change or both?
2. What evidence did you observe
to support that there was a chemical reaction.
Adapted from 365 Simple Science Experiments
by E. Richard Churchill, Louis V. Loeschnig, and Muriel Mandell