Fuels and Heats of Reactions Flashcards
Define organic chemistry.
Organic chemistry is the study of the compounds of carbon
What is a hydrocarbon?
A hydrocarbon is a compound that contains carbon and hydrogen only
Define fossil fuels.
Fossil fuels are fuels that were formed from the remains of plants and animals that lived millions of years ago
What is a saturated compound?
A saturated compound is one in which there are only single bonds between the atoms in the molecule
Define a homologous series.
5
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 (CH2) unit
What are structural isomers?
Compounds with the same molecular formula but different structural formulas
What is an unsaturated compound?
An unsaturated compound is one that contains one or more double or triple bonds between the atoms in a molecule
What is an aliphatic compound?
An organic compound that consists of open chains of carbon atoms and closed chain compounds (rings) that resemble them in chemical properties
Define an aromatic compounds.
Aromatic compounds are compounds that contain a benzene ring structure in their molecule
Define auto-ignition.
Auto-ignition is premature ignition (explosion) of the petrol-air mixture before normal ignition of the mixture by a spark takes place
What is octane number?
The octane number of a fuel is a measure of the tendency of the fuel to resist knocking
Define catalytic cracking.
Catalytic cracking is 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
Define heat of reaction.
Heat of reaction is the heat change when the numbers of moles of reactants indicated in the balanced equation for the reaction react completely
Define heat of combustion.
The heat of combustion of a substance is the heat change when one mole of the substance is completely burned in excess oxygen
What is the kilogram calorific value of a fuel?
The kilogram calorific value of a fuel is the heat energy produced when 1kg of the fuel is completely burned in oxygen
Define bond energy.
Bond energy is the average energy required to break one mole of a particular covalent bond and to separate the neutral atoms completely from each other
Define heat of neutralisation.
Heat of neutralisation is the heat change when one mole of H+ ions from an acid reacts with one mole of OH- ions from a base
Define heat of formation.
The heat of formation of a compound is 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
Define Hess’s Law
Hess’s Law states that if a chemical reaction takes place in a number of stages, the sum of the heat changes in the separate stages is equal to the heat change if the reaction is carried out in one stage
Define The Law Of Conservation of Energy
The Law of Conservation of Energy states that energy cannot be created or destroyed but can only be converted from one form of energy into another
