The Effect of Concentration on the Rate of the Reaction
Between Sulphuric Acid and Calcium Carbonate.
November 2018
1 Research Question
How does the change in concentration of sulphuric acid affect its rate of reaction when reacted
with calcium carbonate?
2 Background
My favourite topic in the I.B. Chemistry syllabus has always been chemical kinetics. One thing
that I have noticed throughout life is that not all reactions occur at the same speed. Some
reactions, such as rusting, can take a very long tie, while other reactions, such as the frying of an
egg, occur rather quickly. I have always been intrigued by what it is that makes some reactions
occur faster than others and whether it is possible to speed up or slow reactions.
The Collision theory states that for a reaction to occur, reactant particles need to react with
sufficient energy and proper orientation. While there are many factors that can increase the rate
of reaction, such as temperature and pH level, increasing the concentration of the reactants causes
an increase in the rate of reaction because reactants collide successfully more frequently. This in
turn occurs because there are more particles with sufficient energy and proper orientation per unit
volume. Therefore, the rate of reaction increases.1
Sulphuric acid and calcium carbonate react to produce calcium sulphate, carbon dioxide and
water.
sulphuric acid + calcium carbonate − > calcium sulphate + carbon dioxide + water
H2 SO4 (aq) + CaCO3 (s) −−→ CaSO4 (aq) + CO2 (g) + H2 O(l)
2
This reaction plays a significant role in the environmental issue of acid rain. Sulphuric acid
itself is produced from the reaction of sulphur dioxide with water and atmospheric oxygen.
H2 O(l) + SO2 (g) −−→ H2 SO3 (aq)
2 SO2 + O2 (g) −−→ 2 SO2 (g)
H2 O(1) +SO3 (g) −−→ H2 SO2 (aq)
3
While sulphur dioxide can exist naturally in the atmosphere as a result of volcanic eruptions
1 C., Brown & M., Ford, Higher Level Chemistry, Pearson Education Limited, Edinburgh Gate, Harlow, 2014.,
p. 278.
2 AusTute, ‘The Chemistry of Acid Rain’, Austute [website], 8 April 2018,
http://www.ausetute.com.au/acidrain.html, accessed 19 September 2018.
3 C., Brown & M., Brown, op. cit., p. 395.
1
, and release by oceanic algae, it is very commonly formed nowadays from sulphur, a by-product of
coal-burning in power stations. This is attributed to increased human consumption of fuel since
the Industrial Revolution and linked to the wider phenomenon of climate change. Rainwater is
normally acidic (pH=5.6) because of the presence of dissolved carbon dioxide which forms car-
bonic acid and leads to the release of hydrogen ions. However, the term acid rain refers to rain
which has a pH below 5.6 as a result of the dissolution of sulphur dioxide in rainwater.4
Its name may not sound like it but acid rain has bitter, heart-wrenching effects on our envi-
ronment. It harms our plants, causing leaching (the removal of important minerals such as M g 2 +
before plants can absorb them). Without these nutrients, plants are unable to undergo photo-
synthesis or ultimately grow. Acid rain poses a great risk to lakes as man finish cannot survive
in conditions below pH of 5. At such conditions, toxic Al3 + ions are leach out and reduce the
ability of fish to obtain oxygen by interfering with their gills. The concerning nature of acid rain
are quite self-evident.5
I knew I wanted to investigate this issue and explore kinetics because I am passionate about
both. However, when I began to conduct my research, I was surprised to find that there were
no literature values on the effect of concentration of sulphuric acid on its reaction with calcium
carbonate. As an inquirer, I decided that I would find these values myself.
3 Hypothesis
If the concentration of sulphuric acid is increased, then the rate of reaction between sulphuric acid
and calcium carbonate will increase, because there will be more reactant particles available for
successful collisions, which will then lead to a higher rate of reaction. It is predicted that as the
concentration of sulphuric acid is increased, the time taken for the reaction to reach the end-point
(60 mL on the gas syringe) will increase as a result of more successful collisions.
4 Variables
How This Is Altered/Measured
Independent
Five concentrations were used in this investigation
Variable: Con-
(1.00mol dm−3 , 0.80mol dm−3 , 0.60mol dm−3 , 0.40mol dm−3 , 0.20mol dm−3 ).
centration of
The different concentrations were reached by dilution. E.g. 40 mL sulphuric
sulphuric acid −3
acid and 10 mL water to make up a concentration of 1.00×40
10+40 = 0.80mol dm .
(mol dm−3 )
Dependent
Variable: The
rate of reac-
tion. This is
determined by The rate of reaction is the inverse of the mean time taken for the reaction
the time taken between calcium carbonate and sulphuric acid to reach the endpoint of 60mL
for the reaction on the gas syringe (±2.5mL), or the time taken for the carbon dioxide released
to reach its to reach this end-point. This is measured with a stopwatch.
endpoint (60
mL on the
gas syringe),
measured in
mL/s.
4 ibid., p. 395.
5 ibid., p. 397.
2
Between Sulphuric Acid and Calcium Carbonate.
November 2018
1 Research Question
How does the change in concentration of sulphuric acid affect its rate of reaction when reacted
with calcium carbonate?
2 Background
My favourite topic in the I.B. Chemistry syllabus has always been chemical kinetics. One thing
that I have noticed throughout life is that not all reactions occur at the same speed. Some
reactions, such as rusting, can take a very long tie, while other reactions, such as the frying of an
egg, occur rather quickly. I have always been intrigued by what it is that makes some reactions
occur faster than others and whether it is possible to speed up or slow reactions.
The Collision theory states that for a reaction to occur, reactant particles need to react with
sufficient energy and proper orientation. While there are many factors that can increase the rate
of reaction, such as temperature and pH level, increasing the concentration of the reactants causes
an increase in the rate of reaction because reactants collide successfully more frequently. This in
turn occurs because there are more particles with sufficient energy and proper orientation per unit
volume. Therefore, the rate of reaction increases.1
Sulphuric acid and calcium carbonate react to produce calcium sulphate, carbon dioxide and
water.
sulphuric acid + calcium carbonate − > calcium sulphate + carbon dioxide + water
H2 SO4 (aq) + CaCO3 (s) −−→ CaSO4 (aq) + CO2 (g) + H2 O(l)
2
This reaction plays a significant role in the environmental issue of acid rain. Sulphuric acid
itself is produced from the reaction of sulphur dioxide with water and atmospheric oxygen.
H2 O(l) + SO2 (g) −−→ H2 SO3 (aq)
2 SO2 + O2 (g) −−→ 2 SO2 (g)
H2 O(1) +SO3 (g) −−→ H2 SO2 (aq)
3
While sulphur dioxide can exist naturally in the atmosphere as a result of volcanic eruptions
1 C., Brown & M., Ford, Higher Level Chemistry, Pearson Education Limited, Edinburgh Gate, Harlow, 2014.,
p. 278.
2 AusTute, ‘The Chemistry of Acid Rain’, Austute [website], 8 April 2018,
http://www.ausetute.com.au/acidrain.html, accessed 19 September 2018.
3 C., Brown & M., Brown, op. cit., p. 395.
1
, and release by oceanic algae, it is very commonly formed nowadays from sulphur, a by-product of
coal-burning in power stations. This is attributed to increased human consumption of fuel since
the Industrial Revolution and linked to the wider phenomenon of climate change. Rainwater is
normally acidic (pH=5.6) because of the presence of dissolved carbon dioxide which forms car-
bonic acid and leads to the release of hydrogen ions. However, the term acid rain refers to rain
which has a pH below 5.6 as a result of the dissolution of sulphur dioxide in rainwater.4
Its name may not sound like it but acid rain has bitter, heart-wrenching effects on our envi-
ronment. It harms our plants, causing leaching (the removal of important minerals such as M g 2 +
before plants can absorb them). Without these nutrients, plants are unable to undergo photo-
synthesis or ultimately grow. Acid rain poses a great risk to lakes as man finish cannot survive
in conditions below pH of 5. At such conditions, toxic Al3 + ions are leach out and reduce the
ability of fish to obtain oxygen by interfering with their gills. The concerning nature of acid rain
are quite self-evident.5
I knew I wanted to investigate this issue and explore kinetics because I am passionate about
both. However, when I began to conduct my research, I was surprised to find that there were
no literature values on the effect of concentration of sulphuric acid on its reaction with calcium
carbonate. As an inquirer, I decided that I would find these values myself.
3 Hypothesis
If the concentration of sulphuric acid is increased, then the rate of reaction between sulphuric acid
and calcium carbonate will increase, because there will be more reactant particles available for
successful collisions, which will then lead to a higher rate of reaction. It is predicted that as the
concentration of sulphuric acid is increased, the time taken for the reaction to reach the end-point
(60 mL on the gas syringe) will increase as a result of more successful collisions.
4 Variables
How This Is Altered/Measured
Independent
Five concentrations were used in this investigation
Variable: Con-
(1.00mol dm−3 , 0.80mol dm−3 , 0.60mol dm−3 , 0.40mol dm−3 , 0.20mol dm−3 ).
centration of
The different concentrations were reached by dilution. E.g. 40 mL sulphuric
sulphuric acid −3
acid and 10 mL water to make up a concentration of 1.00×40
10+40 = 0.80mol dm .
(mol dm−3 )
Dependent
Variable: The
rate of reac-
tion. This is
determined by The rate of reaction is the inverse of the mean time taken for the reaction
the time taken between calcium carbonate and sulphuric acid to reach the endpoint of 60mL
for the reaction on the gas syringe (±2.5mL), or the time taken for the carbon dioxide released
to reach its to reach this end-point. This is measured with a stopwatch.
endpoint (60
mL on the
gas syringe),
measured in
mL/s.
4 ibid., p. 395.
5 ibid., p. 397.
2
