Difference between revisions of "En-en adult card 23 hindered calcification process"

From Climate Fresk
Jump to navigation Jump to search
m (Minor corrections)
m (Link add for Memo)
Line 17: Line 17:
=== Consequences ===
=== Consequences ===
* [[En-en_adult_card_29_pteropods_and_coccolithophores|Pteropods and Coccolithophores]]
* [[En-en_adult_card_29_pteropods_and_coccolithophores|Pteropods and Coccolithophores]]
== Other possible links ==
=== Other consequences ===
* [[En-en adult card 27 marine biodiversity|Marine biodiversity]] Calcification problems do not only affect pteropods and coccolithophores. Coral reefs are also affected, for example, so this link is acceptable.


[[fr:Fr-fr_adulte_carte_23_problèmes_de_calcification]]
[[fr:Fr-fr_adulte_carte_23_problèmes_de_calcification]]

Revision as of 10:57, 9 April 2021

Card #23: Hindered Calcification Process

Causes Consequences
Front of the card "Hindered Calcification Process"


When the pH drops, the formation of calcium carbonate (and more specifically, of calcified shells) becomes more difficult.

Explanation

The formation of limestone (calcification) follows the chemical reaction Ca++ + 2HCO3- ⇔ CaCO3 + H2O + CO2

It requires the presence of bicarbonate ions (HCO3-). However, the quantity of these ions in water depends on the pH: in water, carbon dioxide, carbonic acid, bicarbonate ions and carbonates ion are in equilibrium, depending on the pH :

CO2 + H2O ⇔ H2CO3 ⇔ H+ + HCO3- ⇔ 2 H+ + CO32-.

The addition of an acid shifts the equilibrium towards the left of the equation. In other words, if the pH drops, there are fewer bicarbonate ions, making it more difficult for organisms to build their shells.

Correction

Causes

Consequences

Other possible links

Other consequences

  • Marine biodiversity Calcification problems do not only affect pteropods and coccolithophores. Coral reefs are also affected, for example, so this link is acceptable.