Hooked on Science: Bleeding paper

Materials

• Goldenrod paper
• Baking soda
• Water
• Vinegar
• Paper plates

Instructions

STEP 1: Mix 1/4 cup baking soda with 1/4 cup of warm water in a paper plate. Dip the palm of your hand into the baking soda and water. Describe and classify the baking soda and water by its observable properties.

STEP 2: Slap your hand onto a piece of goldenrod paper and observe. Describe what happened.

STEP 3: Pour 1/4 cup vinegar into a new paper plate. Dip the palm of your hand into the vinegar. Describe and classify the vinegar by its observable properties.

STEP 4: Slap your hand onto a new piece of goldenrod paper and observe. Describe what happened. Compare the baking soda and water-slapped goldenrod paper to the vinegar-slapped goldenrod paper. Describe the differences. How can goldenrod paper be used to make observations and measurements to identify materials based on their properties?

Explanation

The goldenrod paper turns bright red when slapped with the palm of your hand, which is covered with baking soda and water. Goldenrod paper is made from a dye that is a pH indicator. Goldenrod paper turns bright red when exposed to a base, such as ammonia or baking soda, and turns a bright yellow when exposed to an acid, such as vinegar or lemon juice.