Magic Sign

[15 Minutes]

Chemicals are grouped together because of common properties. Acids are a group of sour chemicals. They contain hydrogen. When a food tastes sour, like lemon juice or vinegar, it is usually an acid. Bases are the
opposite of acids. They usually feel slippery or soapy. Acids can neutralize or "cancel out" bases. Acids and bases will turn an indicator a different color. Try this experiemnt to observe the changes in color.

You'll need:

• 1 Ex-Lax pill • rubbing alcohol (ADULT SUPERVISION) • jar • paintbrush • white paper • Windex

What to do:

1. If possible, print out these directions. Read them through together before you begin.
2. Together, gather everything you'll need and always remember science safety.
3. With your child, dissolve 1 Ex-Lax pill in 30 ml (2 Tablespoons + 1 teaspoon) of rubbing alcohol in a jar.
4. Using a paintbrush, let your child paint a message on the white paper.
5. Let the paper dry.
6. Ask your child to spray the white paper with Windex. Watch the secret message appear!
7. You and your child may re-spray it several times before the message dissolves away.
8. You may keep the solution in the refrigerator in a labeled jar for 1 year.

Useful information:

Ex-Lax contains the chemical phenophthalein which is an indicator that is colorless in acid and pink in a base. Windex contains the base ammonia giving the message a pink color.