C7: Organic Chemistry

Question 1

How is crude oil made?

Answer 1

Plankton buried underwater and compressed over a long time

Question 2

What does crude oil consist of?

Answer 2

Hydrocarbons (Molecules made from only carbon & hydrogen) of different lengths

Question 3

What are the 2 types of hydrocarbons?

Answer 3

Alkanes & Alkenes

Question 4

What are alkanes made up of?

Answer 4

• Single-covalently bonded carbon atoms surrounded by hydrogen atoms (we say alkanes are saturated)
• Hydrogen makes 1 bond
• Carbon makes 4 bonds

Question 5

What must hydrocarbons in crude oil be separated into before they can be used?

Answer 5

Fractions

Question 6

How does fractional distillation work?

Answer 6

• Hydrocarbons evaporated and rise up the fractionating column where they recondense at different heights
• Longer alkanes have higher boiling points due to more energy needed to overcome the stronger intermolecular forces, so they recondense lower down the column
• Gases at top
• Liquid and thicker oil collect in the middle
• Top = really flammable
• Bottom = really viscous

Question 7

What is the equation for complete combustion?

Answer 7

Fuel + oxygen -> carbon dioxide + water

Question 8

What is the equation for incomplete combustion?

Answer 8

Fuel + oxygen -> carbon monoxide/carbon + water

Question 9

What alkenes have higher viscosity?

Answer 9

Longer ones

Question 10

What alkenes are more flammable?

Answer 10

Shorter ones

Question 11

What can hydrocarbons be used to make?

Answer 11

Solvents, lubricants, detergents and polymers (used to make plastics)

Question 12

What are polymers made from?

Answer 12

AlkEnes

Question 13

What is an alkene?

Answer 13

A hydrocarbon with at least one double covalent bond
Alkenes are unsaturated

Question 14

How do we test for alkenes?

Answer 14

Bromine water turns from orange to colourless
This is due to the bromine atoms bonding to the alkene by breaking the double bond. The molecule has been saturated

Question 15

What is a problem with crude oil?

Answer 15

The demand for shorter alkanes is much higher compared to longer ones

Question 16

What is cracking?

Answer 16

Breaking longer alkanes into a shorter alkane and an alkene

Question 17

What does catalytic cracking require?

Answer 17

-Zeolite catalyst
-Temp of 550 degrees celsius

Question 18

What does steam cracking require?

Answer 18

-No catalyst
-Higher temperature at >800 degrees celsius

Question 19

What is an alcohol?

Answer 19

-An organic molecule with an -OH (hydroxyl) function group
-Always ends with -ol

Question 20

What is the equation for complete combustion involving alcohol?

Answer 20

Alcohol + oxygen -> carbon dioxide + water

Question 21

What is the equation for incomplete combustion involving alcohol?

Answer 21

Alcohol + oxygen -> carbon monoxide/carbon + water

Question 22

What do ethanol + sodium make?

Answer 22

Sodium ethoxide + hydrogen

Question 23

What does an alcohol produce when it is oxidised without combustion?

Answer 23

A carboxylic acid (-COOH)

Question 24

What are polymers?

Answer 24

Long chained organic molecules of repeating sections made from monomers

Question 25

What happens in addition polymerisation?

Answer 25

-Monomers joined together -Must contain a double bond, which breaks in order to produce a single bond to bond to the next monomer

Question 26

What is condensation polymerisation?

Answer 26

The polymerisation of different monomers that have two functional groups on the ends of the molecules

Question 27

What does a carboxylic acid + alcohol produce?

Answer 27

An ester + water

Question 28

What happens when an alcohol with -OH on both end reacts with a carboxylic acid with -COOH on both ends?

Answer 28

Makes a polyester while water is also produced

Question 29

What do amino acids contain?

Answer 29

-An amino group (-NH2) -A carboxyl group (-COOH)

Question 30

What can amino acids be polymerised to make?

Answer 30

Polypeptides and proteins

Question 31

What is DNA (deoxyribonucleic acid)

Answer 31

- A two-stranded polymer made from monomers called nucleotides - Double helix structure

Question 32

What is starch a polymer of?

Answer 32

Glucose

Question 33

What is cellulose a polymer of?

Answer 33

Beta-glucose

Question 34

What is a hydrocarbon?

Answer 34

A compound made up from hydrogen and carbon only

Question 35

What does cracking long hydrocarbons using heat and a catalyst produce?

Answer 35

Short alkanes and alkenes

Question 36

What is complete combustion?

Answer 36

- Lots of oxygen - Roaring blue flame

Question 37

What is incomplete combustion?

Answer 37

- Restricted oxygen - Orange flame

Question 38

What is hydrogenation/hardening?

Answer 38

- Alkenes + hydrogen -> Alkenes - Done at 60 degrees C + nickel catalyst

Question 39

What is hydration?

Answer 39

- Alkenes + water -> Alcohol - Alkenes + hydrogen -> Halo alkene

Question 40

What are uses of alcohol?

Answer 40

- Drinking - Solvent

Question 41

What happens when an alcohol reacts with sodium?

Answer 41

Fizzes

Question 42

What happens when an alcohol reacts with oxygen?

Answer 42

Burns

Question 43

What happens when an alcohol reacts with water?

Answer 43

Dissolves

Question 44

What is the equation for fermentation?

Answer 44

- Sugar -> ethanol + carbon dioxide - Yeast, 37 degrees C

Question 45

What are uses of carboxylic acids?

Answer 45

- Vinegar

Question 46

What happens when a carboxylic acid reacts with a carbonate?

Answer 46

It fizzes

Question 47

What are the 4 bases and what do they bond with?

Answer 47

- A, C, T, G - A always bonds with T - C always bonds with G

Question 48

What is a gene?

Answer 48

- A section of DNA - Holds the information for making amino acids and proteins

Question 49

What is the sugar phosphate backbone?

Answer 49

2 strands that go up the side around the DNA