AP Environmental Science Practice Quiz: Ocean Acidification
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Test your understanding with short quizzes. This quiz has 11 questions to check your progress.
Question 1 of 11
All Questions (11)
A) An increase in the pH of the oceans, making them more alkaline.
B) A decrease in the salinity of the oceans due to melting ice caps.
C) A decrease in the pH of the oceans, making them more acidic.
D) An increase in the overall temperature of the oceans.
Correct Answer: C
The provided text explicitly states that ocean acidification is the 'decrease in pH of the oceans'. A lower pH value indicates higher acidity.
A) Increased solar radiation
B) Increased CO2 concentrations in the atmosphere
C) Runoff of agricultural fertilizers
D) Underwater volcanic activity
Correct Answer: B
The content specifies that ocean acidification is 'primarily due to increased CO2 concentrations in the atmosphere'.
A) The oceans absorb a large part of the CO2 from the atmosphere.
B) CO2 in the atmosphere creates acid rain, which falls into the ocean.
C) Increased CO2 warms the planet, which in turn heats the ocean and lowers its pH.
D) Atmospheric CO2 blocks sunlight, preventing photosynthesis by marine plants.
Correct Answer: A
The text states, 'As more CO2 is released into the atmosphere, the oceans, which absorb a large part of that CO2, become more acidic.'
A) Burning of fossil fuels
B) Vehicle emissions
C) Deforestation
D) Industrial water pollution
Correct Answer: D
The text lists the burning of fossil fuels, vehicle emissions, and deforestation as activities that increase atmospheric CO2, leading to ocean acidification. Industrial water pollution is not mentioned in this context.
A) It increases the water temperature, causing them to expel their symbiotic algae.
B) It reduces the amount of dissolved oxygen available for coral respiration.
C) It makes it difficult for them to form shells due to the loss of calcium carbonate.
D) It increases the growth of competing seaweed and algae.
Correct Answer: C
The content directly states that 'ocean acidification damages coral because acidification makes it difficult for them to form shells, due to the loss of calcium carbonate.'
A) As atmospheric CO2 increases, ocean pH also increases.
B) As atmospheric CO2 decreases, ocean pH also decreases.
C) Atmospheric CO2 levels do not affect ocean pH.
D) As atmospheric CO2 increases, ocean pH decreases.
Correct Answer: D
The text explains that increased atmospheric CO2 is absorbed by the oceans, causing them to 'become more acidic.' A more acidic solution has a lower pH value.
A) Sodium chloride
B) Silicon dioxide
C) Calcium carbonate
D) Potassium iodide
Correct Answer: C
The text explicitly links the damage to corals to 'the loss of calcium carbonate,' which is essential for building their shells and skeletons.
A) Increasing soil erosion, which smothers coral reefs with sediment.
B) Reducing the amount of oxygen released into the atmosphere.
C) Increasing atmospheric CO2 concentrations, which leads to a decrease in ocean pH.
D) Altering global rainfall patterns, which increases freshwater runoff into reef zones.
Correct Answer: C
This question requires connecting a specific activity (deforestation) to its consequence as described in the text. The text lists deforestation as an activity that leads to 'increased CO2 concentrations in the atmosphere,' which is the root cause of ocean acidification and subsequent damage to corals.
A) The use of pesticides in agriculture
B) Vehicle emissions
C) The construction of dams on rivers
D) Oceanic oil drilling
Correct Answer: B
The provided content clearly lists 'vehicle emissions' as one of the anthropogenic activities that contribute to increased CO2 concentrations and, therefore, ocean acidification.
A) Burning fossil fuels -> Decreased ocean pH -> Loss of calcium carbonate -> Damage to corals
B) Deforestation -> Increased ocean temperature -> Loss of calcium carbonate -> Damage to corals
C) Vehicle emissions -> Acid rain -> Decreased ocean pH -> Damage to corals
D) Burning fossil fuels -> Increased ocean salinity -> Loss of calcium carbonate -> Damage to corals
Correct Answer: A
This option correctly sequences the events as presented in the text: an anthropogenic activity (burning fossil fuels) causes the primary chemical change (decreased ocean pH/acidification), which leads to a secondary chemical change (loss of calcium carbonate), resulting in a specific biological effect (damage to corals).
A) A physical change in the state of water from liquid to gas.
B) A series of chemical reactions between dissolved CO2 and seawater.
C) A biological process of decomposition that releases acids.
D) A geological process where acidic minerals dissolve into the ocean.
Correct Answer: B
The statement that ocean acidification 'can be expressed as chemical equations' directly implies that chemical reactions are occurring. The context makes it clear these reactions involve the carbon dioxide that the ocean absorbs from the atmosphere.