Diffusion and membrane lab

Lab Station 1
1. Place one drop of food coloring into a beaker of water.
2. Observe what happens for 2-3 minutes.
Where did the food coloring go?
Why do you think the food coloring did what it did?
Lab Station 2
1. Fill a cup with water. Gently touch the surface of the cup of water.
Taste the water.
2. Drop a spoonful of sugar into the water.
3. Taste the water every 15 seconds for 2 minutes.
What happened to the taste of the water?
Could you see a visible change?
What do you think was going on that you couldn’t see?
Lab Station 4
1. Fill a test tube 1/2 full with water.
2. Add 2-3 drops of phenolphthalein to the water.
3. Wrap a piece of cellophane over the mouth of the test tube. Secure it with
a rubber band.
4. Pour a little ammonia into a beaker.
5. Turn your test tube upside down so the cellophane is facing the ammonia.
Hold the test tube over the ammonia, close to it but not touching.
6. Swirl your test tube (careful to not touch ammonia!) and wait a couple of
minutes. Observe the test tube water.
Could you smell the ammonia? What do you think that means about this
What was the ammonia doing with the substance in the test tube? Were they
Lab Station 3
Fill a plastic baggie with a teaspoon of corn starch and a half a cup of water.
Tie bag so it is completely closed and sealed.
Fill a beaker halfway with water and add ten drops of iodine.
Place the baggie in the beaker so that the cornstarch mixture is submerged
in the iodine water mixture.
5. Wait 5-15 minutes and record your observations
What was happening that you could see in this experiment?
What do you think that means about what we can’t see?