Chemistry Paper 2

Question 1

What is the reversible reaction with hydrated copper sulfate (blue crystals)

Answer 1

1.Absorbs heat becoming anhydrous copper sulfate (white powder)-Endothermic process
2.Add water-blue crystals.-Exothermic process

Question 2

What is the test for alkenes

Answer 2

Bromine water test-alkenes will decolourise it, alkanes do nothing

Question 3

Why is cracking useful to attain short hydrocarbons

Answer 3

It can be used for:
.Polymers
.Medicine
.Fuel

Question 4

Alkene reactions

Answer 4

1.Hydrogen-creates an alkane-double bond breaks
2.Water(breaks down to OH- and H+(creates alcohol)+double bond breaks
3.Halides-turns into a haloalkene-double bond breaks

Question 5

What is the general formula for alcohols

Answer 5

CnH2n+1OH
example 2=n
C2H5OH

Question 6

Tests for gases

Answer 6

Chlorine-Bleaches Litmus paper
Oxygen-Re-lights glowing splint
Hydrogen-Squeaky pop on lighted splint
Carbon Dioxide-Turns limewater cloudy

Question 7

For the burning of cations over a Bunsen burner which is which colour

Answer 7

.Potassium-Lilac
.Copper-Green
.Sodium-Yellow
.Lithium-Crimson
.Calcium-Red