2.1.4 Acids

Question 1

What do acids release in solution

Answer 1

H+ ions

Question 2

4 most common acids & their formulae

Answer 2

Hydrochloric acid - HCl
Sulfuric acid - H2SO4
Nitric acid - HNO3
Ethanoic acid - CH3COOH

Question 3

What do bases release in solution

Answer 3

OH- ions

Question 4

3 most common bases and their formulae

Answer 4

Sodium hydroxide - NaOH
Potassium hydroxide - KOH
Ammonia - NH3

Question 5

What happens to strong acids/bases when in solution

Answer 5

They’re fully dissociated into ions

Question 6

When in solution what happens to weak acids/bases

Answer 6

They only partially dissociate into ions

Question 7

What’s the equation for the reaction of neutralisation

Answer 7

H+ (aq) + OH- (aq) —> H2O (l)

Question 8

3 examples of neutralisation

Answer 8

Acid + alkali —> salt + water

Acid + metal carbonate —> salt + water + carbon dioxide

Acid + metal oxide —> salt + water

Question 9

What’s a titration a technique to find

Answer 9

How much of acid is needed to neutralise an alkali

Question 10

What happens during neutralisation

Answer 10

The H+ ions from acid join with the OH-ions from the alkali to form water (pH 7)

Question 11

What’s the ionic eq common to all neutralisations

Answer 11

H+ + OH- —> H2O

Question 12

Titration technique (7)

Answer 12

1. Wash & rinse pipette with alkali
2. Use pipette to measure out a known volume of alkali
3. Place alkali in clean,dry conical flask & add suitable indicator
4. Put acid in burette washed + rinsed with acid, take an initial reading
5. Add acid until indicator changes colour (neutralisation). Take a final reading
6. Calculate acid volume added by subtracting initial from final
7. Repeat

Question 13

What do u repeat titration till

Answer 13

Concordant results are obtained (0.10cm3)