Everyday consumer products

Question 1

What is the alcohol homologous series functional group?

Answer 1

Alcohols (also known as alkanols) are a homologous series containing the functional group -OH known as the hydroxyl group.

Question 2

How do alcohol names end?

Answer 2

Alcohols have an -ol ending in their name.

Question 3

What is the first member of the alcohol homologous series?

Answer 3

The first member of the alcohol series is methanol.

Question 4

When writing the molecular formula of alcohols where should the functional group be written?

Answer 4

When writing the molecular formula of alcohols the functional group is written at the end so that it can be recognised as an alcohol. e.g. C2H5OH

Question 5

What is the alcohol general formula?

Answer 5

CnH2n+1OH

Question 6

When naming branched chains what gets priority?

Answer 6

When naming branched chains the hydroxyl group gets priority.

Question 7

Describe what happens to the melting and boiling point of alcohols when the length of a hydrocarbon chain increases.

Answer 7

As the length of the hydrocarbon chain increases the melting and boiling points increase. This is due to the increasing strength of the inter molecular forces as observed in all other homologous series.

Question 8

Describe the solubility of alcohols as the length of the carbon chain increases.

Answer 8

The first three members of the homologous series are soluble (or miscible with) water but solubility decreases as the length of the carbon chain increases.

Question 9

What are hydrogen bonds?

Answer 9

Intermolecular forces of attraction between ethanol and water are called hydrogen bonds.

Question 10

What are the products of complete combustion of an alcohol.

Answer 10

The products of complete combustion of an alcohol are water and carbon dioxide.

Question 11

Why are alcohols used as fuels?

Answer 11

Alcohols are used as fuels as they burn with a clean flame and are highly flammable.

Question 12

What is often used as a substitute to fossil fuels and why?

Answer 12

Ethanol is sometimes mixed with petrol as a substitute to fossil fuels as it is renewable and does not increase the carbon dioxide level in the environment (carbon neutral).

Question 13

What alcohol is commonly used in alcoholic drinks?

Answer 13

Ethanol is also the commonly known alcohol that is used in alcoholic drinks.

Question 14

Identify four uses of alcohols.

Answer 14

Alcohols are used as fuels
Alcohols are sometimes used as a substitute to fossil fuels
Alcohols are also used in alcoholic drinks.
Alcohols are also used as feedstock chemicals and solvents.

Question 15

What is the carboxylic acid homologous series functional group?

Answer 15

Carboxylic acids (also known as alkanoic acids) are a family of compounds containing the carboxyl functional group (-COOH)

Question 16

What do carboxylic acids’ names end with?

Answer 16

Carboxylic acids have an -oic ending in their name, for example, ethanoic acid. The name tells you the following information:
eth-contains two carbon atoms
an-contains single c-c bond
oic-contains a carboxyl group (-COOH)

Question 17

What gives carboxylic acids their acidic properties.

Answer 17

The carboxyl group gives the molecule acidic properties.

Question 18

Where is the functional group of carboxylic acids written in the molecular formula?

Answer 18

In the molecular formula, the functional group is written at the end so they can be recognised as carboxylic acids. For example ethanoic acid CH3COOH

Question 19

What is the first member of the carboxylic acid series?

Answer 19

The first member of the carboxylic acid series is methanoic acid,

Question 20

What is the general formula for carboxylic acids?

Answer 20

Carboxylic acids have a genral formula CnH2n+1COOH

Question 21

Describe the solubility of carboxylic acids as the length of the carbon chain increases.

Answer 21

Like alcohols, some carboxylic acids are miscible (soluble) with water (as, like the alcohols, they can form hydrogen bonds with water). Methanoic, ethanoic, propanoic and butanoic acids are miscible in water, however the solubility decreases as the size/length of the carbon chain increases.

Question 22

What is the pH of carboxylic acids when dissolved in water?

Answer 22

When dissolved in water they have a pH of less than 7 (acidic).

Question 23

Describe the melting and boiling points of carboxylic acids as the length of the carbon chain increases.

Answer 23

With increasing carbon chain length the melting and and boiling points of carboxylic acids increases, this is due to the increasing strength of intermolecular forces.

Question 24

What are the products of carboxylic acids reacting with bases?

Answer 24

Carboxylic acids react in the same way as other laboratory acids. They react with bases to form the same products as inorganic acids.

Acid+base->salt + water

remember if a base is a carbonate then carbon dioxide is also another product.

Question 25

What is ethanoic acid used to make?

Answer 25

Ethanoic acid is used to make vinegar.

Question 26

How are carboxylic acids made?

Answer 26

Carboxylic acids are made by the chemical oxidation of alcohols. For example ethanol in wine oxidises over time to form ethanoic acid.

Question 27

What are carboxylic acids used as?

Answer 27

Carboxylic acids are used as preservatives (pickling vinegar) and in making soaps and medicines.

Question 28

Why is vinegar used in household cleaning products?

Answer 28

Vinegar is a dilute solution of ethanoic acid which is used in household cleaning products as it is a non-toxic acid.

Question 29

Which carboxylic acids are naturally occurring and where are they found?

Answer 29

Some carboxylic acids are naturally concurring:
methanoic acid is found in nettles and ant stings.
citric acid is found in citrus fruits
lactic acid is found in yogurts.

Question 30

What are the products of carboxylic acids with metals?

Answer 30

Like other acids carboxylic acids will react with any metals above hydrogen in the electrochemical series to produce a salt and hydrogen. the general equation is :
acid + metal->salt + hydrogen.

Question 31

What are reaction of metals with carboxylic acids called?

Answer 31

These reactions are called redox reactions.