Many common household solutions contain acids and bases. The acidity of a solution can be expressed using the pH scale. Acidic solutions have pH values less than 7, basic solutions have pH values greater than 7, and neutral solutions have pH equal to 7.


In the Preliminary Activity, you will gain experience using a pH Sensor as you measure the pH of three solutions: baking soda, milk, and a soft drink. You will then classify the three solutions as acidic, basic, or neutral.

After completing the Preliminary Activity, you will first use reference sources to find out more about household acids and bases and their chemistry before you choose and investigate a researchable question.