DP Chemistry (first assessment 2025)

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Question 23M.2.HL.TZ2.8a

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Date May 2023 Marks available [Maximum mark: 2] Reference code 23M.2.HL.TZ2.8a
Level HL Paper 2 Time zone TZ2
Command term Compare Question number a Adapted from N/A
a.
[Maximum mark: 2]
23M.2.HL.TZ2.8a
(a)

Compare the hydrolytic and oxidative rancidity and contrast the site where the chemical changes occur.

 

Compare rancidity: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

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Contrast reaction site: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

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[2]

Markscheme

Compare rancidity:
«both produce» disagreeable smell/taste/texture/appearance ✓

Contrast reaction site:
hydrolytic reaction occurs at ester link/COOC link AND oxidative reaction occurs at carbon-carbon double bond/C=C ✓

 

Do not accept “double bond” alone for oxidative reaction site.