Additional Organic Chemistry

Question 1

Compounds made of hydrogen and carbon only

Answer 1

Hydrocarbons

Question 2

Families of compounds with similar properties and structures are called what?

Answer 2

Homologous series

E.g. Alkanes and Alkenes

Question 3

Formula for Alkanes

Answer 3

CnH2n+2

Question 4

Formula for Alkenes

Answer 4

CnH2n

Question 5

What is an Isomer?

Answer 5

Same molecular formula, different structural formula

Question 6

What are Alkanes referred to as and why?

Answer 6

Saturated Hydrocarbons because each carbon atom is bonded to four other atoms and so it is unable to bond to anymore

Question 7

What are Alkenes referred to as and why?

Answer 7

Unsaturated Hydrocarbons because double bonds can be broken meaning there is room for another atom to join to each carbon atom (addition reactions)

Question 8

Formula for Alcohols

Answer 8

CnH2n+1OH

Question 9

Ethanol can be made from sugars by what process and using what microorganism?

Answer 9

Fermentation using Yeast

Question 10

Word equation for chemical reaction where enzymes in yeast ferment a sugar solution to produce Ethanol

Answer 10

Glucose –> Carbon dioxide + Ethanol

Question 11

Conditions for fermentation

Answer 11

·Warm temperature because too cold = slow reaction and too hot = enzymes denature
·No air because ethanol will undergo oxidation and produce ethanoic acid

Question 12

How can ethanol be separated from water/ethanol solution?

Answer 12

Fractional distillation

Question 13

Why is ethanol referred to as a “bio-fuel”?

Answer 13

It is made from something natural

Question 14

Advantages of using ethanol as fuel for cars

Answer 14

• Renewable
• Don’t need to use up Crude Oil
• Carbon neutral

Question 15

Disadvantages of using ethanol as fuel for cars

Answer 15

• Requires large amounts of land to grow sugar cane
• Sugar cane needs to grow in warm temperatures
• Deforestation for land to grow sugar cane is bad as trees would take in more carbon dioxide than sugar cane
• No fuel pumps

Question 16

Social and Economic impact of Alcohol

Answer 16

-Social issues:
·Hangovers can lead to lost work or family problems
·Antisocial behaviour (vandalism, violence)
·Accidents (drink driving)
-Health issues:
·Liver damage, strokes, heart failure
·NHS has less money to spend on other illnesses
-Economic impact:
·Tax on alcohol goes to government
·Many employed in alcoholic drinks industry

Question 17

What homologous series of compounds is Ethanoic acid a member of?

Answer 17

Carboxylic acids

Question 18

Why does sulphuric acid react more vigorously than ethanoic acid?

Answer 18

Sulphuric acid is a stronger acid

Question 19

Similarities of Ethanoic acid and Sulphuric acid with metals, carbonates and bases

Answer 19

·Metal:
-Fizzing and Hydrogen gas
-Exothermic (temp rise)
-Salt produced
·Carbonate:
-Fizzing and carbon dioxide gas
-Temp rise
-Salt produced
·Base:
-Soluble salt formed
-Temp rise
-Base dissolves

Question 20

Differences of Ethanoic acid and Sulphuric acid with metals, carbonates and bases

Answer 20

• Sulphuric acid is a strong acid whilst Ethanoic acid is a weak acid
• Sulphuric acid has a faster rate of reaction so reactions are more vigorous with faster fizzing, greater temp rise and bases dissolve quicker
• Sulphate salts
• Ethanoate salts

Question 21

Fire triangle

Answer 21

• Oxygen
• Heat
• Fuel

Question 22

Extinguishing fires using fire triangle

Answer 22

-Heat:
·Cool it down e.g. water
-Fuel:
·Cut trees down in forest fire to stop fire advancing
-Oxygen:
·Fire blanket
·Carbon dioxide extinguisher

Question 23

Why wouldn’t you extinguish oil fire (e.g. burning chip pan) with water?
How would you put out an oil fire?

Answer 23

Water would sink and expand as it boils and becomes a gas. This would force the oil out of the pan.
Fire blanket or carbon dioxide extinguisher to remove oxygen