Tests

Question 1

How to test for non reducing sugar?

Answer 1

Add HCL, boil and cool solution
Add sodium hydrogen carbonate
Add Benedict’s Reagent

Question 2

What is observed in
the Benedict's test for
a reducing sugar if a
reducing sugar is not
present?

Answer 2

Solution remains blue

Question 3

What is observed in
the Benedict's test for
a reducing sugar if a
reducing sugar is
present?

Answer 3

A red precipitate

is formed

Question 4

Why is acid used in
the Benedict’s test for
a non-reducing
sugar?

Answer 4

It hydrolyses the

glycosidic bond

Question 5

Why is sodium
hydrogencarbonate
used in Benedict's
test for a non-
reducing sugar?

Answer 5

Neutralises the
solution as Benedict’s
reagent doesn’t work
in acidic conditions

Question 6

What is the test used

for a reducing sugar?

Answer 6

Add an equal amount
of benedict’s solution
Place in a water bath
for 3 minutes

Question 7

What is observed in
the Benedict's test for
a non-reducing sugar
if a non-reducing
sugar is present?

Answer 7

Brick red precipitate

formed

Question 8

How can starch be

tested for?

Answer 8

Adding potassium

iodide solution

Question 9

What is observed in a

positive starch test?

Answer 9

Black/dark purple

solution is formed

Question 10

Describe the method
for testing for the
presence of proteins

Answer 10

Add Biuret’s reagent
down the side of the
test tube
Shake

Question 11

What is observed in a

positive test for proteins

Answer 11

Purple solution is formed