Organic Chemistry

Question 1

What two elements do hydrocarbons contain?

Answer 1

Hydrogen and Carbon

Question 2

What is the general formula for alkanes

Answer 2

CnH2n+2

Question 3

What two waste products form from the complete combustion of hydrocarbons?

Answer 3

Carbon Dioxide and Water

Question 4

How is crude oil formed?

Answer 4

It’s formed from the remains of plants and animals that died millions of years ago and were buried in the mud. Over millions of years with hight temperatures and pressure the remains turned into crude oil

Question 5

Where are the shortest carbon chains found in the fractional distillation column

Answer 5

At the top

Question 6

Give three products that can be made from crude oil

Answer 6

Petrol, Kerosene, Diesel oil, Heavy fuel oil, BItumen and Liquefied Petroleum Gas

Question 7

Why is cracking used?

Answer 7

Short chain hydrocarbons are flammable so make good fuels and are in high demand. Long chain carbons form thick gloopy liquids like tar which arent useful

Question 8

Give a product of cracking that is used for making plastics.

Answer 8

Alkenes

Question 9

What is an alkene?

Answer 9

Hydrocarbons which have a double bond between two of the carbon atoms in their chain. They have two fewer hydrogens compared to alkanes

Question 10

General formula for alkenes

Answer 10

CnH2n

Question 11

Why do alkenes burn with a smoky flame

Answer 11

Because they undergo incomplete combustion

Question 12

Name the molecule that reacts with ethene when it is hydrogenated

Answer 12

Hydrogen

Question 13

What is used to test for alkenes?

Answer 13

Adding bromine to an alkene will add across the double bond making a colourless dirbomo-compound

Question 14

What type of compounds are used as monomers to make addition polymers?

Answer 14

Unsaturated monomer molecules (alkenes)

Question 15

Give the names and formulas of the the first four alcahols

Answer 15

Methanol-CH3OH
Ethanol-C2H5OH
Propanol-C3H7OH
Butanol-C4H9OH

Question 16

Give the balanced equation for the combustion of methanol

Answer 16

2(CH3OH)+3(O2)–>2(CO2)+4(H2O)

Question 17

Name the gas that is produced when ethanol reacts with sodium

Answer 17

Hydrogen

Question 18

Name the process that converts sugar into ethanol using yeast

Answer 18

Fermentation

Question 19

Why are carboxylic acids considered weak acids?

Answer 19

When dissolved in water they release H+ ions resulting in an acidic solution. However they don’t ionise completely (not all molecules release their H+ ions) so they form a weak acidic solution.

Question 20

Give the general word equation for the reaction of an alcohol and a carboxylic acid.

Answer 20

Alcohol +carboxylic acid—–>(acid catalyst) Ester + Water

Question 21

How many different products are there in a condensation polymerisation reaction

Answer 21

Two-The polymer and a small molecule (eg water)

Question 22

What are polypeptides?

Answer 22

Polymers made from amino acid in condensation polymerisation.

Question 23

What small molecule is lost when two amino acids react together to form a new bond?

Answer 23

Water