Understanding the pH Scale

What does the pH scale measure?

• The color of a solution.

• The temperature of a solution.

• The concentration of solutes in a solution.

• The acidity or alkalinity of a solution.

What is the pH range for acidic substances?

• 4 to 6

• 0 to 3

• 0 to 6.9

• 7 to 14

What pH value is considered neutral?

• 8

• 5

• 6

• 7

What pH range indicates a basic substance?

• pH equal to 7

• pH greater than 7

• pH between 5 and 6

• pH less than 7

What happens to litmus paper in an acidic solution?

• Litmus paper remains unchanged in an acidic solution.

• Litmus paper turns red in an acidic solution.

• Litmus paper turns blue in an acidic solution.

• Litmus paper dissolves in an acidic solution.

What color does pH paper turn in a basic solution?

• Yellow

• Purple

• Blue or green

• Red

What is the pH value of pure water?

• 6

• 7

• 8

• 5

What does a lower pH number indicate about a substance?

• A lower pH number signifies that a substance is less reactive.

• A lower pH number indicates that a substance is more acidic.

• A lower pH number means the substance is neutral.

• A lower pH number indicates that a substance is more basic.

What type of indicator is a universal indicator?

• A pH indicator.

• A temperature indicator.

• A color indicator.

• A conductivity indicator.

How does the strength of an acid change with lower pH values?

• Lower pH values indicate a weaker acid.

• The strength of an acid remains constant regardless of pH values.

• The strength of an acid increases with lower pH values.

• The strength of an acid decreases with lower pH values.