Chem fuels and heats of reaction

Question 1

Organic chemistry

Answer 1

Study of compounds of carbon

Question 2

Hydrocarbon

Answer 2

Compound that contains hydrogen and carbon only

Question 3

Fossil fuels

Answer 3

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

Question 4

Saturated compound

Answer 4

Contains only single bonds between atoms in a molecules

Question 5

Structural isomers

Answer 5

Compounds with the same molecular formula but different structural formulas

Question 6

Homologous series

Answer 6

A series of compounds of similar chemical properties/showing graduations 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 CH3 unit

Question 7

Aliphatic compound

Answer 7

An organic compound that contains a benzene ring structure in their molecule

Question 8

Unsaturated compound

Answer 8

One that contains a double bond or triple bond between atoms

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

Catalytic cracking

Answer 10

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 10

Octane number

Answer 10

Measure of the tendency of the fuel to resist knocking

Question 11

Heat of reaction

Answer 11

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

Question 12

Heat of combustion

Answer 12

Heat change when one mole of a substance is completely burned in excess oxygen

Question 13

Kilogram calorific value

Answer 13

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

Question 14

Bond energy

Answer 14

Average energy required to break one mole of a covalent bond

Question 15

Heat of neutralisation

Answer 15

Heat change when one mole of H+ ions from an acid reacting with one mole of OH- moles from a base

Question 16

Heat of formation

Answer 16

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

Question 17

Hess’s law

Answer 17

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

Question 18

Law of conservation of energy

Answer 18

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