Fuels and Heats of Reactions Flashcards
What are hydrocarbons
Compound that contains carbon and hydrogen only.
What are fossil fuels
Fuels that were formed from the remains of plants and animals that lived millions of years ago.
What is a saturated compound?
There are only single bond between the atoms in the molecule.
What are alkanes
Saturated compounds
What are isomers
Compounds with the same molecular formula but different structural formulas.
What are alkenes
Unsaturated compounds
What is a unsaturated compound
Contains one or more double or triple bonds between the atoms in the molecule.
What is a functional group
Atom or a group of atoms which is responsible for the characteristic properties of an organic compound or series of organic compounds,.
What is a homologous series
A series of compounds of similar chemical properties, showing gradation 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 is an aliphatic compound
Organic compound that consists of open chains or carbon atoms and close chain compounds(rings) that resemble them in chemical properties.
What is an aromatic compound?
Compounds that contain a benzene ring structure in their molecules.
Fractional distillation of crude oil
RPN KDL FB
Refinery gas - 25
Petrol - 50
Naphtha - 100
Kerosene - 200
Diesel - 300
Lubricating Oil - 400
Fuel oil - 450
Bitumen - 500
What is a mercaptan
Sulfur compound added to gas(LPG) to give it a smell
What is pre-ignition?
Early explosion that can occur if the mixture isn’t correct.
What is auto-ignition
Premature ignition (explosion) of the petrol-air mixture before normal ignition of the mixture by a spark takes place.
What is the octane number
Measure of the tendency of a fuel to resist knocking
What are the factors for a high octane number
- Short chain
- Lots of branching
- Cyclic Structure
What is Isomerisation
Changing straight chained compounds into their isomers. Compounds are now more branched
What is Catalytic cracking
The breaking down of long chain hydrocarbon molecules by the action of heat and catalysts into short chain molecules. An alkene is always produced.
What is dehydrocyclisation
Use of catalysts to for ring compounds from straight chained compounds.
What is bond energy
The average energy required to break up one mole of a substance of a particular covalent bond and to separate the neutral atoms completely from each other
What is the Heat of Neutralisation
Heat change when one mole of H+ ions from an acid reacts with one mole of OH minus ions from a base
What is specific heat capacity
The amount of energy required to raise the temperature of 1kg of a substance by 1K
What are exothermic reactions?
Reactions that release heat (any combustions reaction)
What are endothermic reactions?
Reactions that take in heat (salt in water)
What is the heat of reaction
The heat change when the number of moles of reactants indicated in the balanced equation react completely.
What is the heat of combustion
The heat change when one mole of a substance is completely burned in excess oxygen
What is the heat of formation?
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.
What is Hess’s Law
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.
What is the kilogram calorific value?
Heat energy produced when 1kg of the fuel is completely burned in oxygen.
