One of the Buffers That Contribute to PH Stability in Human

question 38

Multiple Choice

One of the buffers that contribute to pH stability in human blood is carbonic acid (H₂CO₃) . Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HCO₃⁻) and a hydrogen ion (H⁺) . (See figure.)
$\underset{\text { Carbonic acid }}{\mathrm{H}_{2} \mathrm{CO}_{3}} \rightleftharpoons \underset{\text { Bicarbonate ion }}{\mathrm{HCO}_{3}^{-}}+\underset{\text { Hydrogen ion }}{\mathrm{H}^{+}}$

If the pH of blood drops, one would expect ________.

• A) a decrease in the concentration of H₂CO₃ and an increase in the concentration of HCO₃⁻
• B) the concentration of bicarbonate ions (HCO₃⁻) to increase
• C) the HCO₃⁻ to act as a base and remove excess H⁺ by the formation of H₂CO₃
• D) the HCO₃⁻ to act as an acid and remove excess H⁺ by the formation of H₂CO₃

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