Acids and bases

• Science
• Secondary Education

Acids and bases 

Grade -9

may 10, 2020

OBJECTIVES

1.Describe the pH scale

2.different ways pH is measured 

Place the following 

1. Battery acid

2. water

3. Ammonia 

4.Water

5.detergent

How is pH measured ?

1. pH indicators

2. pH testing strips 

3. pH meters 

ACIDS 

pH LESSTHAN 7

LESSER pH stronger is the acid 

Has hydrogen ions 

bases

pH more than 7

stronger the base more the pH

has hydroxide ions 

Indicators 

An indicator is a compound that changes color at different values when it reacts with acidic or basic solutions

pH strip 

The strips contain an indictaor that changes color over a range of pH values 

pH meter 

most accurate way of finding pH 

It has an electrode sensitive to the hydronium ion 

1. What would you add to a solution with a pH 1.5 to obtain a solution with a pH of 7?

1. milk(pH 6.4)
2. vinegar (pH 3.0)
3. lye (pH 13.0 )
4. coffee(pH 5.0)

2.What do acids and bases have in common?

1. they both produce the same ions when dissolved in water
2. in foods, they both impart a similar taste
3. they both can be harmful to skin and eyes
4. they both have similar pH ranges

3.What is the pH of a neutral solution?

1. 0
2. 1
3. 7
4. 14

4.Which has the highest concentration of H3O+ ions?

1. vinegar
2. acid rain
3. pure water
4. windex

5. Which ions are present in the greatest amount in a solution with a pH of 8.5?

1. hydrogen ions
2. hydronium ions
3. hydroxide ions
4. oxygen ions

Write any three differences between acids and bases