Acids and Alkali

Question 1

When a substance dissolves in water it makes a ____________

Answer 1

Solution

Question 2

Name 2 characteristic of Acids

Answer 2

1. Acids and corrosive
2. They have a sour taste.

Question 3

Weak acids are not ____________ and are found in many of our foods

Answer 3

Corrosive

Question 4

3 e.g of weak acids are

Answer 4

1. Citric acid- Citrus fruits like lemon and
   orange
2. Lactic Acid – Sour milk
3. Acetic Acid – Vinegar

Question 5

3 e.g of strong acids are

Answer 5

1. Hydrochloric acid
2. Sulphuric acid
3. Nitric acid

Question 6

Name 3 characteristics of alkalis

Answer 6

1. Alkalis have a bitter taste.
2. Alkalis are slimy to touch
3. Strong alkalis are corrosive

Question 7

3 e.g of alkalis

Answer 7

1. soap
2. toothpaste
3. detergents

Question 8

Examples of strong alkalis

Answer 8

1. Sodium hydroxide
2. Potassium hydroxide
3. Calcium hydroxide

Question 9

Examples of Weak Alkalis

Answer 9

1. Magnesium hydroxide
2. Ammonium hydroxide

Question 10

How do we know if a given solution is acidic, alkaline or neutral?

Answer 10

We make use of Indicators

Question 11

What are indicators?

Answer 11

Indicators tell us if a solution is acidic, alkaline or neutral.

Question 12

How do they indicate whether a solution is acid, alkaline or neutral?

Answer 12

By changing their colour in acidic, alkaline and neutral solutions.

Question 13

What does red cabbage extract do?

Answer 13

Red cabbage extract changes colour in acidic and alkaline solutions.
❖ Red cabbage extract turns Red in an Acidic solution.
❖ Red cabbage extract turns Blue in a Neutral solution.
❖Red cabbage extract turns Yellow in an Alkaline solution.

Question 14

What happens if you mix an acid and an alkali together?

Answer 14

A salt is formed

Question 16

The chemical reaction is…

Answer 16

Acid + Alkali —> Salt + Water

Question 17

What is neutralisation?

Answer 17

When an acid mixes with an alkali in equal proportion it forms a neutral solution