alkenes

Question 1

what are alkenes

Answer 1

unsaturated hydrocarbons

Question 2

general formula

Answer 2

CnH2n

Question 3

all alkenes have what type of bond

Answer 3

a double carbon bond

Question 4

the double carbon bond means

Answer 4

alkenes can react in ways that alkanes can’t

Question 5

first 4

Answer 5

ethene
propene
but-1-ene
pent-1-ene

Question 6

how can unsaturated carbons make more bonds

Answer 6

by opening up the C=C bond and allowing incoming atoms to form another single bond with each carbon atom of the functional group

Question 7

are they more reactive than alkanes

Answer 7

much more

Question 8

why are they more reactive than alkanes

Answer 8

as the double bond can break and let new atoms attach

Question 9

bromination of alkenes is when

Answer 9

alkenes undergo addition reactions simple molecules atoms add across the C=C bond

Question 10

when bromine is added with an alkene,

Answer 10

dibromoalkane is formed

Question 11

bromination of alkenes also works with

Answer 11

any halogen and alkene in which the halogen atoms add to the carbon atoms across the C=C bond

Question 12

when testing for alkenes, why is bromine water used instead of bromine

Answer 12

its safer

Question 13

what colour is bromine water

Answer 13

orange

Question 14

when bromine water is added to n alkane, what happens

Answer 14

it remains orange as alkanes don’t have double bonds, so bromine remains in the solution

Question 15

when bromine water is added to alkenes, what happens

Answer 15

the bromine bonds add across a C=C bond, so solution decolourises