Science: Chapter 14- Acids and Alkali

What are acids?

What are acids?

Substances that contain hydrogen ions when dissolved in water.

What are alkalis?

Substances that contain hydroxide ions when dissolved in water.

Give some examples of acids.

• Ethanoic acid

• Sulfuric acid

• Nitric acid

Give some examples of alkalis.

• Ammonia

• Sodium Hydroxide

• Potassium Hydroxide

State the use of ethanoic acid.

Cooking

What is the use of sulfuric acid.

Used in car batteries

What is the use of nitric acid?

Making fertilizers

What is the use of ammonia?

Making fertilizers

What is the use of sodium hydroxide?

Making soap

What is the use of potassium hydroxide?

Making alkaline batteries

What are the characteristics of acids?

• Corrosive

• Sour taste

What are the characteristics of alkalis?

• corrosive

• Soapy

• Bitter taste

Test for acids

Blue litmus paper turns red.

Test for alkalis

Red litmus paper turns blue.

pH scale of acids

1-6

pH scale of alkalis

8-14

What are indicators?

Substances that can change color depending on acidity and alkality of substance

What are the 4 indicators?

• Red litmus paper

• Blue litmus paper

• pH paper

• Universal indicator solution

What does it mean when the UIS and pH paper turns yellow/orange?

Weak acid

What does it mean when the UIS and pH paper turn red?

Strong acid

What does it mean when the pH paper and UIS turn blue?

Weak alkali

What does it mean when the UIS and pH paper turn purple?

Strong alkali

What is neutralization?

Reaction of acid and alkali to form salt and water.

Final pH of neutralization?

pH7

Examples of neutralization in daily life?

• Shampoo + Conditioner

• Food stuck between teeth + Toothpaste