Corrosiveness of Soda

Purpose

To determine which type of soft drink is the most corrosive – this will help determine which type of soft drink is most harmful to tooth enamel.

The American Dental Association (ADA) has established that drinking soft drinks in excess can damage tooth enamel. Which type of soft drink is the worst? The hypothesis is that the darker colored soft drinks will remove tarnish from the pennies better than the lighter colored soft drinks and the distilled water.

Required materials

• 1 small bottle of Coca Cola
• 1 small bottle of Pepsi
• 1 small bottle of Dr. Pepper
• 1 small bottle of Sprite
• 1 small bottle of Mountain Dew
• 1 small bottle of distilled water
• Six plastic cups
• Six tarnished pennies
• Journal or logbook
• Measuring cup
• Permanent marker for labeling

One week.

Step-By-Step Procedure

• 1. Fill a plastic cup with 1 cup (measured) of the Coca Cola soft drink. Make sure each cup is labeled with the liquid that is contained within it.
• 2. Repeat step one with the remainder of the cups, filling each one with a different soft drink and finally, the water.
• 3. Drop each of the tarnished pennies in a separate cup. The penny that is soaking in the cup of distilled water will be your control.

Note

You may need an adult’s help with purchasing the items listed under “Required Materials.”

Observation

Observe the tarnished pennies each day, recording data in your journal or logbook each time you observe them. You may need to take the pennies out of the cups for a few minutes to fully view them. Make sure you write notes and answer several questions about your experiment. Is one type of soda visibly reducing the amount of tarnish present on the penny? Do the lighter sodas take the tarnish off the pennies faster than the darker sodas or do the darker sodas take the tarnish off the pennies faster than the lighter sodas? Do the lighter sodas change color as the tarnish is removed? How does this compare to how much tarnish is on the penny that is soaking in the distilled water?

Result

If the hypothesis is correct, the darker colored sodas will remove the tarnish from the pennies better than the lighter sodas. Based on this information, which soft drink do you believe is harder on a person’s tooth enamel?

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