[Campbell Biology P.102] Refer to Figure 3.12. Which of the following chemical reactions dir... | Practice Question

Refer to Figure 3.12. Which of the following chemical reactions directly explains why ocean acidification negatively impacts marine organisms that form shells or skeletons from calcium carbonate CaCO3 ?

  • A: CO2 + H2O → H2CO3
  • B: H2CO3 → H+ + HCO3-
  • C: H+ + CO3^2- → HCO3-
  • D: CO3^2- + Ca^2+ → CaCO3

Explanation

Figure 3.12 and the text "As seawater acidifies, the extra hydrogen ions combine with carbonate ions CO3²¯ to form bicarbonate ions HCO3¯ , thereby reducing the carbonate ion concentration" explicitly state that H+ + CO3^2- → HCO3- reduces the carbonate ions needed for calcification.