Developing Fuels

Question 1

Standard enthalpy change of combustion

Answer 1

Enthalpy change when one mole of a fuel is burned completely in oxygen under standard conditions

Question 2

Standard Enthalpy change of formation

Answer 2

Enthalpy change when one mole of a compound in its standard state is formed from its elements in their standard states

Question 3

Enthalpy change of reaction

Answer 3

Enthalpy change when molar quantities of reactants stated in the equation react together under standard conditions

Question 4

Entropy

Answer 4

A measure of the number of ways that particles in a substance can be arranged

Question 5

Exothermic

Answer 5

Reaction gives our heat energy to surroundings, delta H is negative

Question 6

Endothermic

Answer 6

Reaction that takes in heat energy from surroundings, delta H is positive

Question 7

Specific heat capacity

Answer 7

The heat energy required to increase the temperature of 1g of a substance by 1K

Question 8

Standard states

Answer 8

Physical states of an element at 298K, 1 atmospheric pressure

Question 9

Catalytic cracking

Answer 9

Thermal decomposition of long chain hydrocarbons into shorter chains, some have double bonds

Question 10

Fractional distillation

Answer 10

Separation of substances with different boiling points (I.e crude oil) by evaporation then condensation at different temperatures

Question 11

Knocking/ Autoignite

Answer 11

When fuel/oxygen mixture ignited without a spark during compression in an engine

Question 12

Octane number

Answer 12

Measure the tendency of petrol mixture to auto ignite after compression (without spark)

Question 13

Volatility

Answer 13

The ease of evaporation of a compound (more volatile means lower boiling point)

Question 14

Zeolite

Answer 14

Mineral containing Al, Si and O that contains pores into which hydrocarbons can fit. Used as catalyst and as molecular sieve in oil refining.

Question 15

Heterozygous catalyst

Answer 15

Catalyst that is in a different physical state to the reactants

Question 16

Isomerisation

Answer 16

Reaction in which one isomer is turned into another (i.e used in oil refinery to convert straight chain to beaches chain alkanes)

Question 17

Reforming

Answer 17

Reaction in which straight chain molecules are converted into cyclic aromatic compounds by removal of H2 using Pt catalyst

Question 18

Catalyst poison

Answer 18

Substance that is adsorbed strongly to the catalyst surface preventing the adsorption of the usual reactants

Question 19

Biofuel

Answer 19

Fuel that is prepared form living raw material (I.e ethanol from cane sugar, carbon neutral)

Question 20

Oxygenate

Answer 20

Substances containing oxygen

Question 21

Alcohols

Answer 21

Homologous series with functional group -OH

Question 22

Aliphatic

Answer 22

Acyclic or cyclic compounds that are non-aromatic (no benzene rings)

Question 23

Alkane

Answer 23

Hydrocarbons with general formulae CnH2n+2

Question 24

Arene/Aromatic

Answer 24

Cyclic compounds containing rings of delocalised electrons (eg benzene)

Question 25

Ether

Answer 25

Compound containing C-O-C group, isomer of alcohol

Question 26

Homologous series

Answer 26

A series of compounds with the same general formula, in which each member differs from the next by a CH2 group

Question 27

Isomer

Answer 27

Molecules with the same number of each type of atom bonded in a different arrangement

Question 28

Saturated

Answer 28

Contains no double cc bonds

Question 29

Unsaturated

Answer 29

Contains double CC bonds

Question 30

Addition

Answer 30

Reaction in which two molecules bond and no other product is formed

Question 31

Electrophile

Answer 31

A molecule or ion that can except a pair of electrons to form a bond to an electron rich atom

Question 32

Addition polymerisation

Answer 32

Polymerisation in which small monomers bonded to formal long chain molecules with no other products

Question 33

Carbocation

Answer 33

Carbon with a positive charge

Question 34

Co-polymer

Answer 34

Polymer found form two different monomers

Question 35

Energy transferred

Answer 35

mass of water * SHC of water (4.18h * change in temperature

Question 36

Enthalpy of combustion (equation)

Answer 36

Heat energy transferred (j) dived by amount in fuels (moles)

Question 37

Hess’s law

Answer 37

The Enthalpy change for a reaction is independent of the route taken from reactants to products, providing the conditions stay the same