Alcohols and Haloalkanes Flashcards Preview

A Level Chemistry Year 1 > Alcohols and Haloalkanes > Flashcards

Flashcards in Alcohols and Haloalkanes Deck (124)
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1

What is the general formula of an alcohol?

Cn H2n+1 OH

2

What is the suffix of an alcohol with 2 hydroxyl (OH) groups?

-diol

3

What is a primary alcohol?

An alcohol where the -OH group is attached to a carbon with 1 alkyl group attached

4

What is a secondary alcohol?

An alcohol where the -OH group is attached to a carbon with 2 alkyl groups attached

5

What is a tertiary alcohol?

An alcohol where the -OH group is attached to a carbon with 3 alkyl groups attached

6

What is an alkyl group?

An alkane with a Hydrogen removed e.g CH3

7

What is electronegativity?

The ability of an atom to attract the bonding electrons in a covalent bond

8

Why are alcohols classed as polar molecules?

Because the electronegative hydroxyl groups pulls the electrons in the C-OH bond away from the carbon atom, forming a dipole

9

What dipoles are there in an O-H bond?

ẟ- O-H ẟ+

10

In an alcohol, what does the partial positive charge on the Hydrogen atom in the hydroxyl group cause?

It attracts the lone pairs on an oxygen from a neighbouring molecule, forming a Hydrogen bond

11

What happens, in terms of bonds, when you mix an alcohol with water?

Hydrogen bonds form between the -OH group and the H2O

12

What is the trend in solubility of alcohols as they increase in size?

As alcohols increase in size, they become less soluble in water

13

Why do alcohols become less soluble in water as they increase in size?

Smaller alcohols are more polar, meaning the Hydrogen bonding lets it mix freely with water. In larger alcohols, most of the molecule is a non-polar carbon chain, so there's less attraction for the polar H2O molecules

14

Describe the volatility of alcohols

They have a low volatility

15

Why do alcohols have a low volatility?

Because they can form Hydrogen bonds (strongest type of intermolecular force) meaning it takes more energy to evaporate to a gas

16

What can be said about the boiling point of alcohols?

They have a relatively high boiling point

17

Why do alcohols have a relatively high boiling point?

Because they can form Hydrogen bonds (strongest type of intermolecular force) meaning it takes more energy to break the intermolecular bonds

18

What is the name of the reaction when an alcohol reacts with compounds containing Halide ions?

Substitution reaction

19

What does an alcohol turn into when undergoing a substitution reaction?

A Haloalkane, as the -OH group is replaced by the halide

20

What catalyst is used in an alcohol substitution reaction?

An acid catalyst, such as H2SO4 (sulfuric acid)

21

How do you make an alkene from an alcohol?

You can do an elimination reaction, which eliminates the water from the alcohol

22

What is a substitution reaction?

A reaction where some atoms from one reactant are swapped with atoms from another reactant

23

What is an elimination reaction?

A reaction in which a pair of atoms or group of atoms are removed from an organic compound

24

What 2 possible catalysts are used for the elimination reaction of alcohols?

Concentrated H2SO4 (sulfuric acid)
Concentrated H3PO4 (phosphoric acid)

25

How do alcohols undergo an elimination reaction?

They are heated in the presence of a catalyst

26

What is the water molecule that is eliminated from an alcohol when making an alkene made up of?

A hydroxyl group and a hydrogen atom that was bonded to a carbon atom adjacent to the hydroxyl carbon

27

What are the products for the combustion of alcohols?

Water and carbon dioxide

28

What is the oxidising agent used for the oxidation of alcohols?

Acidified potassium dichromate (VI)
(K2Cr2O7 / H2SO4)

29

What are the 2 products, in chronological order of formation, for the oxidisation of primary alcohols?

Oxidised to aldehydes and then to carboxylic acid

30

What is the only product of the oxidation of secondary alcohols?

Ketones