Can Ketchup Clean a Penny?

The video tutorial explores how to clean dull pennies using various household items. It begins with an introduction to the materials needed for the experiment, including dish soap, cola, vinegar, salt, lemon juice, and ketchup. Predictions are made about which substances will clean the pennies best. The experiment is conducted, and results show that acidic substances like vinegar and lemon juice clean the pennies effectively by dissolving copper oxide. The video concludes with an explanation of why acids work and encourages further experimentation with different substances.

What did you observe about the effectiveness of different cleaning solutions used in the experiment?

Explain why acidic substances are effective in cleaning pennies.