Question

Due to ocean acidification when the ocean becomes more acidic, what happens to the pH level of the ocean?

• A. The pH level goes down
• B. The pH level stays the same
• C. The pH level goes up
• D. The pH level becomes zero

Answer 1

The Correct Option is A

Ocean acidification refers to the process by which the ocean becomes more acidic due to the absorption of carbon dioxide (CO₂) from the atmosphere. When CO₂ dissolves in seawater, it forms carbonic acid, which dissociates into bicarbonate ions and protons, leading to an increase in the concentration of hydrogen ions (H+). This increase in H+ concentration results in a decrease in the pH level of the ocean.

To understand why the pH level goes down, we need to recall that pH is a scale used to specify the acidity or basicity of an aqueous solution. It is important to know the formula:

\(pH = -log10[H⁺]\)

Where [H⁺] represents the concentration of hydrogen ions. Since pH is inversely related to [H+], an increase in hydrogen ions due to ocean acidification leads to a reduction in pH value, thus making the solution more acidic.

Accordingly, the correct answer to the question is: The pH level goes down.

Answer 2

When ocean acidification occurs and the ocean becomes more acidic, the pH level goes down.

Additional Context:

• Normal ocean pH is about 8.1 (slightly basic)
• Acidification occurs when CO₂ dissolves in seawater forming carbonic acid
• Since Industrial Revolution, ocean pH has dropped by 0.1 units (30% increase in acidity)
• Impacts marine life especially organisms with calcium carbonate shells/skeletons
• Different from:
  • pH going up = more basic/alkaline
  • pH 0 = strongly acidic (not occurring in oceans)

Correct Answer: (1) The pH level goes down.