Chapter 14 Alcohols and Chpt 15Haloalkanes

Question 1

What is the functional group of alcohols?

Answer 1

OH

Question 2

How would you describe the water solubility of alcohols?

Why?

Answer 2

High

Because the OH functional group forms strong hydrogen bonds with H20

Question 3

Does solubility of alcohols increase as chain length increases or as it decreases?

Answer 3

Solubility increases as chain length decreases because the CH2 part of the molecule doesnt form H bonds with the water molecules so as there are less of them more of the compounds will form

Question 4

Is the volatility of alcohols high or low?

Why?

Answer 4

Relatively low
Because the force of attraction is stronger than the London forces present between other molecules such as alkanes, therefore alcohols are less volatile than other organic molecules which have a similar molecular mass

Question 5

Define primary alcohol

Answer 5

The OH group of the alcohol is attached to 1 C atom which is attached to a maximum of 1 other C atom

Question 6

Define secondary alcohol

Answer 6

The OH group is attached to a C atom which is attached to 2 other C atoms

Question 7

Define tertiary alcohol

Answer 7

The OH group is attached to a C atom that is attached to 3 other C atoms

Question 8

When alcohols burn in sufficient oxygen what do they form?

Answer 8

CO2 H20

Question 9

What is the oxidising agent for the oxidation of alcohols?

Answer 9

Acidified dichromate

Question 10

When primary alcohols are distilled what do they form?

Answer 10

Aldehydes

Question 11

When primary alcohols are refluxes what do they form?

Answer 11

Carboxylic acids

Question 12

Define reflux

Answer 12

Continual heating and condensing of a reaction mixture

Question 13

What is formed when a secondary alcohol is distilled?

Answer 13

A ketone

Question 14

Can a secondary alcohol be refluxed?

Answer 14

No

Question 15

Can a tertiary alcohol be oxidised?

Answer 15

No

Question 16

What are the colour changes when you oxidise alcohols?

Answer 16

Orange —-> green

Question 17

Define elimination

Answer 17

When 2 atoms or groups are removed resulting in the formation of a double bond

Question 18

When an alcohol undergoes elimination what is removed from the alcohol and what is formed?

Answer 18

H20 is removed

An alkene is formed

Question 19

What conditions are required for dehydration of ethanol?

Answer 19

Heat
Reflux
Concentrated H2SO4

Question 20

Define substitution

Answer 20

When an atom or group is replaced by another atom or group

Question 21

What is formed when a substitution reaction with a halide ion occurs?

Answer 21

A haloalkane

Question 22

What conditions are required for substitution?

Answer 22

Reagents - sodium halide and H2SO4
Temperature
Reflux

Question 23

Define haloalkane

Answer 23

An alkane in which one or more H atoms has been replaced with a halogen atom

Question 24

Define nucleophile

Answer 24

An electron pair donor

Question 25

What conditions are required for nucleophilic substitution?

Answer 25

NaOH - aqueous Hot Reflux

Question 26

A haloalkane + aqueous sodium hydroxide —->

Answer 26

Alcohol and sodium halide

Question 27

Define hydrolysis

Answer 27

A reaction with water or aqeuous hydroxide ions that breaks a chemical compound into 2 compounds

Question 28

The rate of hydrolysis reactions of haloalkanes depends on the ——- ——- —-

Answer 28

Halogen atom attached

Question 29

Describe the bond enthalpies between C and a halogen as you go down the group

Answer 29

They decrease

Question 30

``` Which haloalkane is the most reactive our of CH3F CH3Cl CH3Br CH3I Why? ```

Answer 30

CH3I Because the bond enthalpies are weakest which means the least amount of energy is needed to overcome the forces

Question 31

How would you carry out an experiment to find the relative rates of reactions for haloalkanes?

Answer 31

Set up 3 test tubes with 1cm3 of ethanol and 2 drops of the haloalkane Place them in a water bath at 50

Question 32

What is the precipitate colour of chloroalkane?

Answer 32

White precipitate

Question 33

What is the precipitate colour of bromoalkane?

Answer 33

cream precipitate

Question 34

What is the precipitate colour of iodoalkane?

Answer 34

Yellow precipitate

Question 35

Why is an iodoalkane expected to react more quickly than a bromoalkane?

Answer 35

Because C-I is the weakest bond so it needs the least amount of energy to be overcome