Work over a tray that will contain liquid spills. Fill a beaker or glass container halfway with distilled vinegar. Add water until the container is three-fourths full. Tell the children that vinegar is an acetic acid and will react with certain other chemicals.
Fill a teaspoon with baking soda and quickly drop it into the vinegar and water container. Have the children discuss the sudden bubbling up of the liquid when the two chemicals react together. Ask what they see, hear and smell during the experiment.
Place the end of a funnel into a deflated balloon. Spoon 2 tsps. of baking soda through the funnel into the balloon.
Fill a beaker or glass container with an opening of about 1 inch halfway with distilled vinegar. Add water until the container is three-fourths full.
Pull the end of the balloon over the container of liquid. Shake the balloon slightly so the baking soda falls into the liquid. Have the children discuss why the balloon is inflating. Talk about the gas effect of the chemical reaction when mixing vinegar and baking soda.
Work over a surface that bleach cannot harm. Spread out some brightly colored washcloths.
Have the children use a pipette or eye-dropper to drop spots of bleach onto the cloths. Discuss the chemical changes that happen when the bleach removes the color from the places it comes into contact with on the washcloths.
Give each child a clear 1-cup container filled with water.
Have the children put drops of liquid watercolor paints into their cup of water, and observe the changes. Mention that this is a physical change, not a chemical one.
Instruct the children to use their pipettes to drop a small amount of bleach into the colored water. Allow them to add more bleach until their water is clear. Tell the children that the bleach caused a chemical change by removing the color from the water.