Chapter 21 - Fuels and Heats of Reaction

Question 1

Hydrocarbon

Answer 1

A compound that contains carbon and hydrogen only

Question 2

Fossil fuels

Answer 2

Fuels that were formed from the remains of plants and animals that lived millions of years ago

Question 3

Saturated compound

Answer 3

One in which there are only single bonds between the atoms in the molecule

Question 4

Homologous series

Answer 4

A series of compounds of similar chemical properties
Showing gradations in physical properties
Having a general formula for its members
Each member having a similar method of preparation
Each member differing from the previous member by a unit

Question 5

Structural isomers

Answer 5

Compounds with the same MOLECULAR formula but different structural formulas

Question 6

Unsaturated compounds

Answer 6

One that contains one or more double or triple bonds between the atoms in the molecule

Question 7

Aliphatic compound

Answer 7

An organic compound that consists of open chains of carbon atoms and closed chain compounds that resemble them in chemical properties

Question 8

Aromatic compound

Answer 8

Compounds that contain a benzene ring structure in their molecules

Question 9

Auto ignition

Answer 9

Premature ignition of the petrol-air mixture before normal ignition of the mixture by a spark takes place

Question 10

Octane number

Answer 10

A fuel is a measure of the tendency of the fuel to resist knocking

Question 11

Catalytic cracking

Answer 11

The breaking down of long chain hydrocarbon molecules by the action of heat and catalysts into short chain molecules for which there is greater demand

Question 12

Heat of reaction

Answer 12

The heat change when the numbers of moles of reactants indicated in the balanced equation for the reaction react completely

Question 13

Heat of combustion

Answer 13

A substance is the heat of change when one mole of the substance is completely burned in excess oxygen

Question 14

Kilogram calorific value of a fuel

Answer 14

The heat of energy produced when 1kg of the fuel is completely burned in oxygen

Question 15

Bond energy

Answer 15

The average energy required to break mole of a particular covalent bond and to separate the neutral atoms completely from each other

Question 16

Heat of neutralisation

Answer 16

The heat change when one mole of H+ ions from an acid reacts with one mole of OH- ions from a base

Question 17

Heat of Formation of a compound

Answer 17

The heat change that takes place when one mole of a compound in its standard state is formed from its elements in their standard states

Question 18

Hess’s Law

Answer 18

If a chemical reaction takes place in a number of stages, the sum of heat changes in the separate stages is equal to the heat change if the reaction is carried out in one stage

Question 19

Law of Conservation of Energy

Answer 19

Energy cannot be created or destroyed but can only be converted from one form of energy into another

Question 20

Organic chemistry

Answer 20

The study of the compounds of carbon

Question 21

Sources of hydrocarbons

Answer 21

Fossil fuels:
Coal
Methane
Crude oil

Question 22

Methane

Answer 22

• Formed from materials of plant and animal origin, decayed manure (anaerobic bacteria)
• Heats the farm
• Contributes to greenhouse effect