cracking and the alkanes

Question 1

fractions containing _______ hydrocarbon molecules are in ____ demand than those containing _______ hydrocarbon molecules

Answer 1

larger, less, smaller

Question 2

how can large hydrocarbon molecules be broken down (cracked)?

Answer 2

using steam or catalytic cracking

Question 3

what are the conditions for steam cracking?

Answer 3

mix vapour with steam and heat to very high temperature

Question 4

what are the conditions for catalytic cracking?

Answer 4

heat to 500c and pass over hot catalyst

Question 5

what are the products of cracking?

Answer 5

smaller hydrocarbons and another types of hydrocarbons called alkenes

Question 6

what are alkenes?

Answer 6

hydrocarbons that contain carbon - carbon double bond

Question 7

what happens as bromine water reacts with alkene?

Answer 7

turns from orange/brown to colourless

Question 8

what happens to bromine water when added to an alkane?

Answer 8

wage remains orange/brown

Question 9

what are alkenes used to produce?

Answer 9

polymers

Question 10

what is the general formula for a homologous series of alkenes

Answer 10

CnH2n

Question 11

alkene molecules are _______

Answer 11

unsaturated

Question 12

what are the first 4 alkenes in the series?

Answer 12

ethene, propene, butene, pentene

Question 13

what is the functional group in an alkene?

Answer 13

C=C

Question 14

what happens when alkenes react with oxygen?

Answer 14

tend to burn with smoky flames due to incomplete combustion

Question 15

what do alkenes produce when reacted with water?

Answer 15

alcohols

Question 16

how do alkenes react with halogens?

Answer 16

halogen attaches to both carbons that formed with double bond

Question 17

what is bromine water used to test for?

Answer 17

an alkene; the bromine water will change from orange/brown to colourless when added to an alkene