7 Organic Seperate 1

Question 1

What are alkenes

Answer 1

A different type of hydrocarbon which is more reactive than an alkane

Question 2

What are alkenes used for?

Answer 2

As a starting material to make more useful chemicals

Question 3

How do you test for an alkene?

Answer 3

React it with bromine water

Question 4

What is the colour change when an alkene reacts with bromine water?

Answer 4

Turns from orange to colourless

Question 5

What is an alkene?

Answer 5

A hydrocarbon with a double bond

Question 6

What is the general formula for alkenes?

Answer 6

CnH2n

Question 7

What does unsaturated means?

Answer 7

Contains double bonds (which could become C-H bonds)

Question 8

What are the first four alkenes?

Answer 8

Ethene, propene, butene, pentene

Question 9

What are the four reactions of alkenes?

Answer 9

Combustion, with water, with hydrogen and with halogens

Question 10

How is the combustion of alkenes different to combustion of alkanes?

Answer 10

Alkenes usually react by incomplete combustion so burn with smoky flames

Question 11

Why are the reactions of alkenes with hydrogen, water and halogens known as “addition” reactions?

Answer 11

Because new atoms are being added to the molecule by breaking the double bond

Question 12

What is the product from the reaction of an alkene with hydrogen?

Answer 12

An alkane

Question 13

What conditions are necessary in the reaction of alkenes with hydrogen?

Answer 13

60oC, Nickel catalyst

Question 14

What is the product from the reaction of an alkene with a halogen?

Answer 14

An alkane with two halogen atoms where the double bond used to be

Question 15

What is the product from the reaction of an alkene with steam?

Answer 15

An alcohol

Question 16

What conditions are necessary for the reaction of alkenes with steam?

Answer 16

High temperature, high pressure, catalyst

Question 17

What functional group do all alcohols have?

Answer 17

OH

Question 18

Name and draw the first four alcohols

Answer 18

Methanol, ethanol, propanol, butanol (ethanol pictured)

Question 19

What happens when an alcohol reacts with sodium?

Answer 19

It forms a sodium salt (e.g. sodium ethoxide from ethanol) and releases hydrogen gas.

Question 20

What are the products of a combustion reaction involving an alcohol and oxygen?

Answer 20

Carbon dioxide and water

Question 21

Write a symbol equation for the reaction of methanol/ethanol/propanol/butanol with oxygen

Answer 21

E.g CH3CH2OH + 5O2 gives 2CO2 + 3H2O

Question 22

Do alcohols dissolve in water?

Answer 22

Yes, they form neutral solutions

Question 23

How do alcohols react with oxidizing agents?

Answer 23

They turn into carboxylic acids

Question 24

What are the main uses of alcohols?

Answer 24

Solvents, ethanol used as drinking alcohol and a biofuel

Question 25

What is fermentation?

Answer 25

The process of turning glucose (a natural sugar) into ethanol

Question 26

What is required for natural fermentation?

Answer 26

Yeast

Question 27

What functional groups do all carboxylic acids have?

Answer 27

COOH

Question 28

Name and draw the first four carboxylic acids

Answer 28

Methanoic acid, ethanoic acid, propanoic acid, butanoic acid (image is ethanoic acid)

Question 29

Why are carboxylic acids weak acids?

Answer 29

Not all their molecules ionise when in water

Question 30

What is the product of a reaction between an alcohol and a carboxylic acid?

Answer 30

An ester