Topic 6 - Organic Chemistry

Question 1

What is a homologous series?

Answer 1

Series of compounds that have similar properties with the same functional group and general formula.

Question 2

What is a functional group?

Answer 2

Group of atoms that give a ‘family’ of organic compounders their characteristic reaction.

Question 3

What are the prefixes

Answer 3

1- meth
2- eth
3- pro
4- but
5- pent
6- hex
7- hept
8- oct
9- non
10- dec

Question 4

What is an addition reaction?

Answer 4

Reaction where 2 (or more) molecules join together to form another molecule.

Question 5

What is a polymerisation reaction?

Answer 5

Reaction where many monomer join together to make a long chain polymer.

Question 6

What is an elimination reaction?

Answer 6

Reaction where atoms/small groups lost from adjacent carbon atoms.

Question 7

What is a substitution reaction?

Answer 7

Reaction where an atom/ group of atoms replaced by another.

Question 8

What is a hydrolysis reaction?

Answer 8

Reaction where molecule split by adding H+ and OH-

Question 9

What is an oxidation reaction?

Answer 9

Reaction in which a species loses an electron.

Question 10

What is a reduction reaction?

Answer 10

Reaction in which a species gains an electron.

Question 11

What is a structural isomer?

Answer 11

Same molecular formula but different structural formulae.

Question 12

What is stereoisomerism?

Answer 12

Same molecular formula and order in which atoms bonded but differ in 3D space

Question 13

What is E/Z?

Answer 13

E - opposite
Z - same
Depends on priority

Question 14

What is cis-trans?

Answer 14

Cis- same group same side
Trans - same groups opposite sides

Question 15

What are alkanes and cycloalkanes?

Answer 15

Saturated hydrocarbons

Question 16

How are alkane fuels obtained?

Answer 16

Fractional distillation, cracking and reforming of crude oil.

Question 17

What is refluxing and when is it used?

Answer 17

• flammable and volatile (turn into gas easily) substances
  -continuous evaporation then condensation
  -often slow reactions
• anti bumping granules in round bottomed flask

Question 18

What is distillation and when is it used?

Answer 18

-gentle heating of mixture
-lowest boiling point evaporates first
-used in making aldehydes from primary alcohols

Question 19

What is a separating funnel and when is it used?

Answer 19

-used if product is insoluble in water
-removes soluble impurities from product
-shake + allow separation
-run off two layers then use drying agent (Magnesium sulfate)
-remove lid to run off

Question 20

What is reforming?

Answer 20

Processing straight chain hydrocarbons into branched chain alkanes and cyclic hydrocarbons for efficient combustion.

Question 21

What are pollutants are produced during process of combustion?

Answer 21

CO, oxides of nitrogen and sulfur, Carbon particulates and unburied hydrocarbons.

Question 22

What does a catalytic converter do?

Answer 22

Removed environmentally polluting molecules from exhaust gases.

Question 23

What is the structure of a catalytic converter?

Answer 23

Contains s quantities of Platinum, Rhodium and Palladium.
-spread over thin honeycomb mesh which increases surface area.

Question 24

What are the stages of the catalytic converter?

Answer 24

NOx + CO molecules attach to catalytic mesh
-weakens bonds -> react more freely
-products released from catalytic mesh

Question 25

Major reactions:

Answer 25

CO+1/2O2 -> CO2
H4C2+3O2->2CO2 +2H2O
2NO +2CO -> N2 +2CO2

Question 26

What are biofuels?

Answer 26

-fuel derived from biomass over short period
-renewable
-make minimal difference to the proportion of atmosphere CO2

Question 27

What are the 3 main types of biofuel?

Answer 27

Biogas
Bioethanol
Biodiesel

Question 28

How is biogas produced?

Answer 28

-produced when organic waste is broken down by micro-organisms anaerobically
-composed of methane and CO2
-large scale produced in anaerobic digestion plants
-often refined my removing methane + other contaminants to produce biomethane.

Question 29

How is bioethanol produced?

Answer 29

-fermentation of plant matter -> often using enzymes or bacteria.
- has to be separated from water -> requires energy
-E10-> 10% ethanol fuel blend
- ethanol has higher octane number + reduces pollutants. -> provides more oxygen

Question 30

How is biodiesel produced?

Answer 30

• refining fats and oils
  -produced by transesterification -> converts fats + oils into biodiesel + glycerin
  -effective alternative to diesel

Question 31

Benefits of alternative fuel:

Answer 31

• considered almost carbon neutral
• Reduce amount of waste going to landill
• could provide money for less developed countries

Question 32

Drawbacks of biofuel:

Answer 32

• high cost
• developed countries don’t be space as land is needed for food production

Question 33

What is a radical?

Answer 33

A species with an unpaired electron - represented by one dot in mechanisms.

Question 34

How is a radical formed?

Answer 34

Formed by homolytic fission of a covalent bond and results in the formation of radicals.

Question 35

What re allènes and cycloalkenes?

Answer 35

Unsaturated hydrocarbons.

Question 36

What is an electrophile?

Answer 36

Electron pair acceptors from an electron rich centre

Question 37

Nitrous oxide hazards:

Answer 37

Form ozone at ground level
Irritates eyes and can cause lung damage, shortness of breath etc

Question 38

Sulfur dioxide hazards

Answer 38

Dissolved in water to make acid rain, destroys trees and vegetation

Question 39

What is the test for c=c bonds (double)?

Answer 39

Add bromine water - from orange to colourless if present

Question 40

What happens to steam in the presence of acid?

Answer 40

Alcohol formed