Halogenoalkanes

Question 1

How do you name a halogenoalkane with more than one halogen?

Answer 1

Alphabetically

Question 2

What is the prefix for a halogenoalkane?

Answer 2

Iodo-
Bromo-
Chloro-

Question 3

What are the three groups that halogenoalkanes can be classed into?

Answer 3

Tertiary
Primary
Secondary

Question 4

What is a primary halogenoalkane?

Answer 4

One carbon is attached to the carbon atom that is joined to the halogen.

Question 5

What is a secondary halogenoalkane?

Answer 5

Two carbons are attached to the carbon atom that is joined to the halogen.

Question 6

What is a tertiary halogenoalkane?

Answer 6

Three carbons are attached to the carbon atom that is joined to the halogen.

Question 7

What kind of reactions can halogenoalkanes undergo?

Answer 7

Elimination or Nucleophillic substitution

Question 8

What is substitution?

Answer 8

Swapping a halogen atom for another atom or group of atoms.

Question 9

What is a nucleophile?

Answer 9

An electron pair donator.

Question 10

Give 3 nucleophile examples.

Answer 10

:OH-
:NH3
:CN-

Question 11

What do the curly arrows show?

Answer 11

The movement of the pair of electrons.

Question 12

Where does the curly arrow start and end?

Answer 12

From the lone pair of electrons to the carbon atom. Then from the bond between the carbon and the atom that is being substituted to the atom that is being substituted.

Question 13

What does the rate of a substitution reaction depend on?

Answer 13

The strength of the C-X bond. The weaker the bond, the easier it is to break and the faster the reaction.

Question 14

In group 7, which element forms the weakest C-X bond and which forms the strongest?

Answer 14

Iodine is the weakest and fluorine is the strongest.

Question 15

Define hydrolysis?

Answer 15

The splitting of a water molecule by a reaction with water.

Question 16

What is formed from a nucleophilic substitution with aqueous hydroxide ions?

Answer 16

Alcohol

Question 17

What is the condition needed when using aqueous hydroxide ions?

Answer 17

In warm aqueous solution.

Question 18

What does a reaction with CN form?

Answer 18

Nitrile

Question 19

What is the reagent needed for the nucleophillic reaction with cyanide ions?

Answer 19

KCN dissolved in ethanol

Question 20

What is the condition needed when using cyanide ions?

Answer 20

Heating under reflux

Question 21

Where does the nitrile functional group have to be?

Answer 21

At the end of the group.

Question 22

How would you name a nitrile with 4 carbons?

Answer 22

ButanEnitrile.

Question 23

What is formed from a nucleophilic substitution with ammonia?

Answer 23

Amine

Question 24

What is the reagent needed for the nucleophilic substitution with ammonia?

Answer 24

NH3 dissolved in ethanol.

Question 25

What is the condition needed for the nucleophilic substitution with ammonia?

Answer 25

Heating under pressure.

Question 26

How could you minimise a lower yield of ammonia?

Answer 26

Use excess ammonia

Question 27

What is elimination?

Answer 27

Removal of a small molecule from the organic molecule.

Question 28

What reagent is needed for the elimination reaction with alcoholic hydroxide ions?

Answer 28

Potassium or sodium hydroxide

Question 29

What condition is needed for the elimination reaction with alcoholic hydroxide ions?

Answer 29

In ethanol and heated.

Question 30

What can be formed from unsymmetrical secondary and tertiary halogenoalkanes?

Answer 30

Two or three different structural isomers.

Question 31

What are chloroalkanes and chlorofluoroalkanes used as?

Answer 31

Solvents

Question 32

What are halogenoalkanes used as?

Answer 32

Refrigerants Pesticides Aerosol propellants

Question 33

Why have the uses of halogenoalkanes stopped?

Answer 33

They're toxic and have detrimental effects on the atmosphere.

Question 34

Why is the ozone in the upper atmosphere beneficial?

Answer 34

It absorbs UV radiation.

Question 35

What does ozone do in the lower atmosphere?

Answer 35

It is a pollutant and contributes towards the formation of smog.

Question 36

What did man-made chlorofluorocarbons cause?

Answer 36

A hole in the ozone layer to form.

Question 37

How are chlorine radicals formed in the upper atmosphere?

Answer 37

When energy from UV radiation causes C-Cl bonds in chlorofluorocarbons to break.

Question 38

Suggest two reasons why the use of CFCs was not restricted until several years after Rowland and Molina published their research.

Answer 38

Lack of evidence that ozone was being depleted. Lack of alternatives to CFCs.

Question 39

State how greenhouse gases contribute to global warming (CFCs).

Answer 39

Absorbs infrared radiation because it is a polar molecule.

Question 40

What is the role of hydroxide ions?

Answer 40

Base