Question

Write a hypothesis about the pH level of common household solutions based on what you know about their physical and chemical properties. Use the format of "if . . . then . . . because . . .” and be sure to answer the lesson question "How is pH used to determine if a solution is acidic or basic?”

Answer 1

Sample Response: If a solution is an acid, then it will have a pH below 7, and if the solution is a base, it will have a pH above 7 since the pH value is determined by the concentration of H+ and OH– ions.

Answer 2

If pH is less than seven (pH<7), solution is acidic.

If pH is equal seven (pH = 7), solution is neutral.  

If pH is greater than seven (pH > 7), solution is basic.  

Some examples:

1) Acidic - gastric juices pH 1, lemon juice pH 2.2, tomato juice pH 4.

2) Neutral - salt solution pH 7.

3) Alkaline - baking soda pH 9, bleach pH 13.

pH is a numeric scale used to specify the acidity or basicity of an aqueous solution.