Identification Tests

Question 1

How can you test for an alkene?

Answer 1

Add bromine water or MnO4^-

Question 2

How can you test for an alkane?

Answer 2

Add bromine water and UV light

Question 3

How can you test for a primary alcohol?

Answer 3

Add Cr2O7^2- or MnO4^-

Question 4

How can you test for an amine?

Answer 4

Use moist, red litmus

Question 5

How can you test for a carboxylic acid?

Answer 5

Use moist, blue litmus or Na2CO3

Question 6

What does bromine water identify and how do you know?

Answer 6

Alkanes and alkenes

Alkanes: bromine water is brown and if UV light is added the solution will decolourise

Alkenes: bromine water is brown and the solution will rapidly decolourise is it’s an alkene

Question 7

What does Cr2O7^2- identify and how?

Answer 7

Primary alcohols: the colour changes from orange to green

Question 8

What does moist, red litmus identify and how?

Answer 8

Amines: the colour changes from red to blue

Question 9

What does moist, blue litmus identify and how?

Answer 9

Carboxylic acids: the colour changes from blue to red

Question 10

What does MnO4^- identify and how?

Answer 10

Alkenes and primary alcohols: the colour changes from purple to colourless

Question 11

What does Na2CO3 identify and how?

Answer 11

Carboxylic acids: bubbles of colourless gas form