Qualitative Tesing

Question 1

Protein

Answer 1

Biuret test

Question 2

Starch

Answer 2

Iodine

Question 3

Lipids

Answer 3

Emulsion

Question 4

Reducing sugars

Answer 4

Benedict’s

Question 5

Non reducing sugars

Answer 5

Benedict’s

Question 6

Glucose

Answer 6

Test strips

Question 7

Biuret test

Answer 7

1. Add sodium hydroxide solution.
2. Add copper (II) sulphate solution.

Blue to purple

Question 8

Iodine test

Answer 8

1. Add iodine in potassium iodide solution

brown-orange to blue-black.

Question 9

Emulsion

Answer 9

1. Add ethanol.
2. Pour solution into water.

Solution goes a milky colour.

Question 10

Benedict’s - reducing

Answer 10

1. Add Benedict’s reagent to a sample

heat in a water bath that’s brought to a boil.

blue (to green to yellow to orange) to brick red precipitate, depending on the concentration.

Question 11

Benedict’s test - non reducing sugar

Answer 11

1. Add dilute HCl.
2. Put in a water bath brought to a boil.
3. Neutralise with sodium hydrogen carbonate.
4. Do Benedict’s Test for reducing sugars.

Question 12

Test strips

Answer 12

1. Dip test strip in solution

Colour change will occur if glucose is present. Compare to chart of known colour changes to check for concentration.