Reactions of acids – Experiment report
Results and Observations:
Experiment 1
pH of each acid
pH of 0.1M HCl(aq)
pH of 0.1M
CH3COOH(aq)
Experiment 2
Neutralisation with drops of 1M
sodium hydroxide (NaOH)
Experiment 3
Reactions of each acid with
Copper Oxide (CuO)
Number of drops of 1M
NaOH(aq) to neutralise
0.1M HCl(aq)
Number of drops of 1M
NaOH(aq) to neutralise
0.1M CH3COOH(aq)
Observations:
CuO + 1M HCl(aq)
Observations:
CuO + 1M CH3COOH(aq)
Experiment 4
Reactions of each acid with
marble chips (CaCO3)
Observations:
CaCO3 + 1M HCl(aq)
Observations:
CaCO3 + 1M
CH3COOH(aq)
Experiment 5
Reactions of each acid with
magnesium (Mg)
Observations:
Mg + 1M HCl(aq)
Observations:
Mg + 1M CH3COOH(aq)
Reactions of acids – Experiment report
Discussion
1. In the first tests, you found the pH of the two acids. Both acids were at the same
concentration (0.1 M).
 Why were they compared at the same concentration?
 Why did they have a different pH?
 What can be concluded about the strength of ethanoic acid compared with the
strength of hydrochloric acid? Discuss.
2. Following is the balanced equation for the reaction of ethanoic acid with water. The
CH3COO– ion is termed the ethanoate ion (also known as the acetate ion). Insert the
correct type of arrow in the space. Then explain your reasoning.
CH3COOH(aq) + H2O(l)
CH3COO–(aq) + H3O+(aq)
3. Compare the number of drops of sodium hydroxide used to neutralise each acid. Is
this what you expected? Explain. •
4. Compare the reactions of the two acids with the metal oxide, copper(II) oxide. Which,
if any, appeared to react more vigorously with the metal oxide? Write balanced
equations for the reactions.
5. The limewater test is the standard test for carbon dioxide gas. It goes milky because
the carbon dioxide reacts with the limewater to produce a precipitate of calcium
carbonate. This is the main constituent of marble chips and chalk. The equation for
the reaction is: Ca(OH)2(aq) + CO2(g) ➝CaCO3(s) + H2O(l)
 Did your tests confirm that carbon dioxide gas was produced?
 Was there a difference in the rate of its production? If so, suggest why.
 Write balanced equations for the reactions of the two acids with marble.
6. The ‘pop test’ is the standard test for hydrogen gas. The ‘pop’ sound you hear is a
mini-explosion due to the combustion of hydrogen gas in air, which is a very
exothermic reaction. The equation for the reaction is:
2H2(g) + O2(g) ➝2H2O(l) + energy
 Did your tests confirm that hydrogen gas was produced?
 Was there a difference in the rate of its production? If so, suggest why.
 Was the reaction between the acids and magnesium endothermic or exothermic?
Justify your answer. Write balanced equations for the reactions of the two acids
with magnesium.
Summarise your findings about the reactions of the two acids in your conclusion.