Capter 10 (Chemistry only)

Question 1

What is the main element in all organic compounds?

Answer 1

Carbon

Question 2

What is a homologous series?

Answer 2

A family of compounds with the same functional group

Question 3

What is the general formula for an alkene?

Answer 3

C_nH_2n

_{Note: All alkenes have -ene on the end of their name e.g. pent<strong>ene</strong>}

Question 4

What is the general formula for an alkane?

Answer 4

CnH_2n+2

Note: All alkane have an

-ane on the end of their name e.g. butane

Question 5

What are the products of combustion of an alkene?

Answer 5

Carbon dioxide and water

Question 6

Where in the alkene does a reaction occur?

Answer 6

Across the c=c double bond

Question 7

An alkene reaction with hydrogen produces what new product?

Answer 7

An alkane

e.g. pentene + hydrogen ————-> pentane

Question 8

What conditions are needed to produce an alkane from an alkene?

Answer 8

A catalyst (nickel) and 60⁰C

Question 9

What is the product of the reaction of an alkene with water (steam)?

Answer 9

An alcohol

e.g.

ethene + steam ————-> ethanol

Note: Reaction is reversible so you can break the alcholo back into an alkene and water

Question 10

What is the functional group of an alcohol?

Answer 10

-OH

Note: All alcohols have an -ol at the end of their name e.g. ethanol

Question 11

What is the functional group of a carboxylic acid?

Answer 11

-COOH

Note: All carboxylic acids have -oic acid at the end of their name e.g. butanoic acid

Question 12

How are esters formed?

Answer 12

Esters are formed when a carboxylic acid and an alcohol react together in the presence of an acid catalyst

The first part of the name comes from the alcohol the second part from the carboxylic acid

e.g. ethanol+ butanoic acid ————–> ethylbutanoate

Question 13

What type of acids are carboxylic acids?

Answer 13

Weak organic acids

Question 14

How do you test for carboxylic acids?

Answer 14

Carbon dioxide gas is produced when you add a metal carbonate to carboxylic acid. You will see bubbles and could test the gas using limewater.

Question 15

What is the test for an alkene?

Answer 15

Alkenes turn bromine water colourless. Bromine water tests for C=C bond which is present in alkenes

Question 16

What are esters used for?

Answer 16

Esters have a distinctive smell and they evaporate easily (volatile). They are used in perfumes and food flavourings etc. Many have sweet fruity smells. Esters are found in natural fruits such as strawberries

Question 17

Why can alcohols be used as a fuel?

Answer 17

Alcohols under go combution.

Question 18

How can alcohols be produced?

Answer 18

Fermentation of plant matter using yeast (catalyst).

e.g.

glucose ——-> ethanol + carbon dioxide

Question 19

What is the product formed when an alcohol is oxidised by using a chemical oxidising agent [O} or microbes in the air?

Answer 19

Carboxylic acid and water

Question 20

What are the products of a reaction between alcohol and sodium?

Answer 20

Sodium alkoxide and hydrogen. You will see bubbles of hydrogen and it will be strongly alkaline.

e.g.

sodium + ethanol ———–> sodium ethoxide + hydrogen

Question 21

Can you recall how many carbons are in meth, eth etc…?

Answer 21

prefix:

meth 1 carbons

eth 2 carbons

prop 3 carbons

but 4 carbons

pent 5 carbons

hex 6 carbons

e.g. ethanol would be an alcohol with 2 carbons in its chain

Question 22

Why can’t you produce alcohols higher than 15% using the fermentation process?

Answer 22

The alcohol produced is toxic and above this concentraion it will kill off the yeast (enzymes) so the reaction will stop.

Question 23

Give two uses of alcohols?

Answer 23

• Biofuel
• Good solvent for many organic chemicals

Question 24

What is oxidation?

Answer 24

Gain of oxygen or loss of an electron

Question 25

Why does wine left open to the air turn into vinegar?

Answer 25

Microbes in the air oxidise the alcohol to form a carboxylic acid Note: Vinegar is formed when ethanol (the alcohol found in wines and bears etc) oxidises to form ethanoic acid

Question 26

What is the name ending used fro esters?

Answer 26

- oate e. g. ethan**oate**

Question 27

Alkenes are unsaturated hydrocarbons, what does this mean?

Answer 27

It means there is at least one C=C double bond. Not all the carbon bonds are filled using hydrogens