C6.2 Organic Chemistry

Question 1

What are hydrocarbons

Answer 1

compounds that contain carbon and hydrogen only

Question 2

Alkanes are hydrocarbons, why do they form a homologous series

Answer 2

They have the same general formula.
They are saturated

Question 3

What is the general formula for alkanes

Answer 3

CnH2n+2

Question 4

Name the first 4 straight chain alkanes

Answer 4

Methane, Ethane, Propane, Butane

Question 5

What are the products when alkanes undergo combustion

Answer 5

carbon dioxide and water

Question 6

what is formed when alkanes undergo incomplete combustion

Answer 6

water, carbon monoxide and carbon (soot)

Question 7

what features do alkenes have in common

Answer 7

They have C-C double bond and are unsaturated

Question 8

Give the general formula for alkenes

Answer 8

CnH2n

Question 9

Name the first 4 alkenes

Answer 9

Ethene, propene, butene, pentene

Question 10

What is an addition reaction

Answer 10

An atom/group of atoms combine with a molecule, and no other products are formed

Question 11

What do you see when bromine water is added to alkenes

Answer 11

It goes colourless from orange - brown

Question 12

How do you form alkanes from alkenes

Answer 12

Add hydrogen in the presence of a Nickel catalyst

Question 13

What is the functional group present in alcohols and name it

Answer 13

-OH
Hydroxyl group

Question 14

What do names of alcohols end in

Answer 14

‘ol’

Question 15

Name the first 4 alcohols

Answer 15

methanol, ethanol, propanol, butanol

Question 16

What is formed when alcohols undergo combustion

Answer 16

Carbon dioxide and water

Question 17

What is the functional group present in carboxylic acids

Answer 17

Carboxyl group
-COOH

Question 18

What is the general formula for carboxylic acids

Answer 18

CnH2n+1COOH

Question 19

Name the first 4 carboxylic acids

Answer 19

methanoic acid, ethanoic acid, propanoic acid, butanoic acid

Question 20

How are carboxylic acids made

Answer 20

when alcohols react with oxidising agents in the presence of dilute sulfuric acid

Question 21

What is formed when carboxylic acids react with metals

Answer 21

Salt and hydrogen

Question 22

What is formed when carboxylic acids react with alkalis and bases

Answer 22

Salt and water

Question 23

How are carboxylic acids made

Answer 23

When alcohols react with oxidising agents such as potassium manganate (V11) solution

Question 24

Explain why crude oil is a finite resource

Answer 24

It is non-renewable and is being used up faster than it is being formed

Question 25

Describe and explain fractional distillation

Answer 25

Separating mixture of liquids with different boiling points into different fractions

Question 26

What is cracking

Answer 26

Breaking down large alkanes to smaller alkane and alkene molecules

Question 27

What are the conditions to carry out cracking

Answer 27

High temperature and need a hot catalyst of alumina or silica

Question 28

Why is cracking done ?

Answer 28

It helps to match the supply needed of the smaller, more useful molecules in demand

Question 29

What is addition polymerisation

Answer 29

When monomers add together to form a long chain polymer

Question 30

Give some examples of polymers

Answer 30

polyethene, polypropene, polychloroethene

Question 31

What are the conditions to carry out addition polymerisation

Answer 31

High pressure and a catalyst

Question 32

What are the monomers of DNA

Answer 32

Nucleotides

Question 33

What does a nucleotide consist of

Answer 33

phosphate, deoxyribose, base

Question 34

What are the monomers of a protein

Answer 34

Amino Acids

Question 35

What are the monomers of a carbohydrate

Answer 35

sugars

Question 36

Name the 4 bases found in DNA

Answer 36

Adenine, Thymine, Cytosine, Guanine

Question 37

What happens in a condensation reaction

Answer 37

2 molecules react together to form one larger molecule and one smaller molecule

Question 38

what is an amino group

Answer 38

-NH2

Question 39

What is a carboxyl group

Answer 39

-COOH

Question 40

What is an ester group

Answer 40

-COO-

Question 41

What is an Amide group

Answer 41

-CONH-

Question 42

6 marker question: Compare the structure of DNA, Proteins and Carbohydrates. In your answer, include the similarities and differences between them.

Answer 42

They are polymers. They are made up of monomers. DNA monomers are nucleotides (Phosphate, sugar-deoxyribose, organic base). Proteins are made from amino acids. carbohydrates are made from simple sugars (glucose, & sucrose) DNA contains four different monomers / nucleotides. Proteins contain about 20 different monomers / amino acids - higher Sucrose contains two different simple sugars / glucose and fructose -higher

Question 43

Write a word equation for making polyamide

Answer 43

diamine + dicarboxylic acid  polyamide + water

Question 44

What are polyesters made from

Answer 44

A carboxylic acid with two carboxyl groups also known as dicarboxylic acid. An alcohol with two hydroxyl groups also known as diol

Question 45

How are proteins formed?

Answer 45

Proteins are condensation polymers formed from amino acids. Amino acids have two different functional groups: Amino and a carboxyl group

Question 46

What is the fuel in a hydrogen oxygen fuel cell

Answer 46

The hydrogen-oxygen fuel cell uses hydrogen as its fuel

Question 47

What is produced as a product in the hydrogen oxygen fuel cell

Answer 47

Water

Question 48

Write the reaction at the anode

Answer 48

H2(g) → 2H+ (aq) + 2e-

Question 49

Write the reaction at the cathode

Answer 49

4H+(aq) + O2 (g) + 4e- → 2H2O(g)

Question 50

State some advantages of fuel cells

Answer 50

They have no moving parts They are compact. They are lightweight. Zero emissions of CO2 from cars (H2O only product) Easy access to hydrogen and oxygen from decomposition of water

Question 51

What are the disadvantages of fuel cells

Answer 51

The method we currently use to produce hydrogen uses fossil fuels which produce pollutants and are running out. Fuel cells often use poisonous catalysts which have to be disposed of safely when the fuel cell reaches the end of its life