random stuff i need to know in chem

Question 1

list an example of a natural buffer system and how it works (reactions) (4)

Answer 1

Ocean’s Carbonate buffering system:

• ocean takes in CO₂ from the atmosphere (CO₂(g) ⇄ CO₂(aq))
• converts CO₂ into carbonic acid (H₂CO₃) (CO₂(aq) + H₂O(l) ⇄ H₂CO₃(aq))
• carbonic acid then dissociates in solution initially into bicarbonate ions (HCO₃⁻) and hydrogen ions (H⁺) (H₂CO₃ ⇄ HCO₃⁻ + H⁺)
• the bicarbonat then further dissociates into carbonate and and hydrogen ions (HCO₃⁻ ⇄ CO₃²⁻ + H⁺)

Question 2

leaching cycad fruit (3)

Answer 2

leaching cyasin toxin

• cycad kernels are cut open and grounded to increase surface area (to quicken the process)
• running water is then passed through where a equilibrium is set ( cyasin(s) ⇄ cyasin(aq))
• the running water then takes the aqueous cyasin with it, causing equilibrium to favour the production of aqueous cyasin thus removing the toxin

Question 3

what are the half equations for turning alcohol in carboxylic acid (oxidation and reduction half equations

Answer 3

(MnO₄⁻ + 8H⁺ + 5e⁻➝ Mn²⁺ +4H₂O ) x 4
(C₉H₉OH +H₂O➝ C₃H₇COOH + e⁻ + H⁺ ) x 5
5C₉H₉OH + 4MnO₄⁻ + 12 H⁺➝ 5C₃H₇COOH + 4Mn²⁺ + 11H₂O