Question 36
MediumOriginal questionA few drops of iodine solution are put on a slice of potato and it turns blue-black. This shows that the potato contains
Show the answer and explanation
CorrectNot quiteAnswer B
Correct answer: B
Explanation
Iodine turns blue-black in the presence of starch; this is the standard test for starch.
Worth noting
Fat is tested by a translucent spot on paper, and protein by the violet colour with copper sulphate and caustic soda.
- Concept
- Food test for starch
- Typical timeTypical
- 60 s
- Your timeYours
- —
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