Ocean Acidification

Question 1

ionic product of water

Answer 1

2H2O <=> H3O+ + OH- ; 25 degrees, equal conc, equlibirium

Question 2

why is water an amphiprotic substance?

Answer 2

it can donate and accept a proton

Question 3

pH and pOH calculation

Answer 3

pH + pOH = 14

Question 4

how does water acidify

Answer 4

more hydronium ions enter.

Question 5

explanation: CO2 + H2O <=> H2CO3

Answer 5

carbon dioxide is soluble in the sea and reacts to carbonic acid.

Question 6

explanation: H2CO3 + H2O <=> H3O+ + HCO3-

Answer 6

carbonic acid is weak and partially ionises into hydronium ions and hydrogen carbonate ions.

Question 7

explanation: HCO3- + H2O <=> H3O + CO3

Answer 7

hydrogen carbonate ions further ionise in water, forming hydronium ions and carbonate ions.

Question 8

how do hydronium ions affect alkanity?

Answer 8

the sea is naturally alkaline at pH 8.2, and a decrease by 0.1 represents a 30% increase in H+ concentration.

Question 9

pH equation

Answer 9

pH = -log [H+]

Question 10

[H+] equation

Answer 10

[H+] = 10^-pH mol/L

Question 11

effect of ocean acidification on marine animals

Answer 11

metals and acid make carbon dioxide, water, and salt. shells made of calcium carbonate can dissolve in acid, ionic equation: CaCO3 + 2H+ –> CO2 + H2O + Ca2+. this depletes the habitats of shellfish, which also leads to shortage of food for humans.