Strong acids, weak acids and their reactions

Question 1

What do acids produce in water?

Answer 1

• Protons

Question 2

What do acids do in aqueous solutions?

Answer 2

• Ionise

- H+ ions

Question 3

What are examples of acids in water?

Answer 3

• HCl –> H+ + Cl-

- HNO3 –> H+ + NO3-

Question 4

What do strong acids do in water?

Answer 4

• Ionise completely

- Particles dissociate to release H+ ions

Question 5

What is an example of strong acids in water?

Answer 5

H2SO4 –> 2H+ + SO4^2-

Question 6

What do weak acids do in water?

Answer 6

• Do not fully ionise

- Small proportion of acid particles dissociate to release H+ ions

Question 7

What is the ionisation of a weak acid?

Answer 7

• Reversible reaction

- Sets up equilibrium between undissociated and dissociated acid

Question 8

What is an example of weak acids in water?

Answer 8

• CH3COOH H+ + CH3COO-

Question 9

What is the pH of an acid or alkali?

Answer 9

• Measure of concentration of H+ ions in solution

Question 10

How are the pH values related to the concentration of H+ (aq) ions?

Answer 10

• For every decrease of 1 pH, the concentration of H+ ions increase by a factor of 10
  Factor H+ ions concentration changes by = 10^-x (where x is difference in pH)

Question 11

What is the pH of a strong acid and a weak acid of the same concentration?

Answer 11

• pH of stronger acid is lower than weak acid

Question 12

What does acid strength tell you?

Answer 12

• What proportion of acid molecules ionise in water

Question 13

What is concentration?

Answer 13

• More solute in solution compared to water

Question 14

What is a dilute solution?

Answer 14

• More water compare to solutes

Question 15

Give two examples of bases?

Answer 15

• Metal oxide

- Hydroxide

Question 16

Equation for soluble alkalis:

Answer 16

• Acid + Metal oxide –> Salt + Water

- Acid + Metalhyroxide –> Salt + Water

Question 17

Hydrochloride + Copper oxide –>

Answer 17

Copper chloride + Water

Question 18

Sulfuric acid + Calcium hydroxide –>

Answer 18

Calcium Sulfate –> Water

Question 19

Nitric acid + Magnesium oxide –>

Answer 19

Magnesium nitrate + Water

Question 20

What do acids and metal carbonates produce?

Answer 20

• Salt + Water + Carbon dioxide

Question 21

Equation for Acids and metal carbonates:

Answer 21

Acid + Metal carbonate –> Salt + Water + Carbon dioxide

Question 22

Hydrochloric acid + Sodium carbonate –>

Answer 22

Sodium chloride + Water + Carbon dioxide

Question 23

Sulfuric acid + Calcium carbonate –>

Answer 23

Calcium sulfate + Water + Carbon dioxide

Question 24

Describe the method to make copper sulfate crystals from copper(III) oxide and sulfuric acid?

Answer 24

• Add copper oxide to sulfuric acid, stir
• Warm over bunsen burner (don’t boil)
• Solution turns blue, Copper sulfate formed
• Black excess copper oxide will be seen, filter this out
• Boil water on bunsen burner with copper sulfate solution dish on top
• Stop heating when crystals appear
• Let water evaporate, big crystals will form
• Let solution cool + dry
• Dab with tissue solution of crystals
• (Crystallisation)

Question 25

Why is making copper sulfate crystals from copper(III) oxide and sulfuric acid so special (not really)?