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Question 18M.3.SL.TZ2.8b.i

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Date May 2018 Marks available [Maximum mark: 2] Reference code 18M.3.SL.TZ2.8b.i
Level SL Paper 3 Time zone TZ2
Command term List Question number b.i Adapted from N/A
b.i.
[Maximum mark: 2]
18M.3.SL.TZ2.8b.i

In the generator method of ethanoic acid fermentation, Acetobacter aceti are grown over wood shavings in a fermenter to the point where they form a biofilm.

At the base of the fermenter oxygen is bubbled in, which then rises through the wood shavings. Ethanol drips through the wood shavings. At a suitable temperature the ethanol is converted to ethanoic acid, which is withdrawn from the bottom of the fermenter, and new ethanol is added at the top.

(b.i)

List two abiotic variables that would need to be monitored during this fermentation process.

 

[2]

Markscheme

a. oxygen 

b. temperature 

c. pH levels 

d. CO2

Examiners report

 

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