Chapter 24: Alkanes and Alkenes

All the following "answers" are for your reference only!

The "best" answers are based on your actual experimental results!

 

Experiment 24.1: Reactions of Alkanes

1.   a)  It burns with a blue flame.

b)  The lime water turns milky.

c)   2C₆H₁₄(l) + 19O₂(g) ¾® 12CO₂(g) + 14H₂O(g)

2.   a)  No.

b)  No.

4.

	Tube in dark	Tube in UV
Any colour change?	no colour change	turns colourless
Any fumes in the tube?	no fumes	white fumes
Test the space above the liquid with a wet pH paper	no change	turns red then bleaches
Test the space above the liquid with a glass rod wet with aqueous ammonia	no change	white fumes
Pour the mixture into a beaker of water	no reaction	white fumes given off
Has a reaction occurred?	no	yes

 

In UV light.

The bromine is decolourized. HBr is given off.

 

What you have learnt?

Hexane burns in air to give carbon dioxide and water.

It (is / is not) oxidized by potassium permanganate. It reacts with bromine in (the dark / UV light).

The bromine is (oxidized / reduced) and hydrogen bromide is given off.

 

 

 

Experiment 24.2: Test for unsaturation

1.   It changes from orange to colourless.

2.   It changes from purple to colourless.