A-LevelBiologyBiological molecules9700/12 · May/June 2023 · Q71 Mark
Which set of steps is the best method for conducting the emulsion test for lipids?
AAdd 2 cm³ of water to the sample.
Pour the water into a test-tube containing 2 cm³ of ethanol.
Lipids are present if the mixture becomes cloudy.
BAdd 2 cm³ of ethanol to the sample and shake.
Pour the ethanol into a test-tube containing 2 cm³ of water and boil.
Lipids are present if the mixture becomes clear.
CAdd 2 cm³ of water to the sample and shake.
Pour the water into a test-tube containing 2 cm³ of ethanol and boil.
Lipids are present if the mixture becomes cloudy.
DAdd 2 cm³ of ethanol to the sample and shake.
Pour the ethanol into a test-tube containing 2cm³ of water and shake again.
Lipids are present if the mixture becomes cloudy.
✓ Correct answer
D: Add 2 cm³ of ethanol to the sample and shake. Pour the ethanol into a test-tube containing 2cm³ of water and shake again. Lipids are present if the mixture becomes cloudy.
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