Developing Fuels Flashcards
explain why stereoisomerism can occur in but-2-ene (2 marks)
there is a lack of rotation around the C=C bond
and the groups on each end of the carbon atom are different
number of moles in gas =
vol in dm3 / 24.0
or
vol in cm3 / 24000
what is the ideal gas equation?
pV = nRT
what is R in the gas equation?
gas constant - 8.314
enthalpy change is..
the heat energy transferred in a reaction at a constant pressure
what are the enthalpy change units?
kj mol-1
in an exothermic reaction energy is…
given out to surroundings
in endothermic reactions energy is…
absorbed
in an exothermic reaction delta H is..
negative
in an endothermic reaction delta H is..
positive
bond breaking is an ____ process
endothermic
bond breaking is an _____ reaction
endothermic
enthalpy change of reaction =
total energy absorbed to break bonds - total energy released in making bonds
standard enthalpy change of reaction is…
the enthalpy change when the reaction occurs in molar quantities shown in the chemical equation, under standard conditions
Enthalpy is…..
the energy content stored in a system
standard enthalpy change of combustion is…..
The enthalpy change that takes place when 1 mol of substance reacts completely with oxygen under standard conditions.
standard enthalpy change of formation is….
the enthalpy change that takes place when one mole of a compound is formed from its constituent parts in their standard states under standard conditions
standard enthalpy change of neutralisation is…
the enthalpy change that takes place when 1 mol of hydrogen ions react with 1 mol of hydroxide ions to form water under standard conditions
Hess’ law is when
a reaction can take place by more than one route and the initial and final conditions are the same, the total enthalpy change for each route is the same
for combustion data in hess cycles the arrow points…
downwards
for formation data in hess cycles the arrow points…
up
fractional distillation is…
separation of a liquid mixture into fractions differing in boiling point, by means of distillation.
using a fractionating column
hydrocarbons are made of…,
hydrogen and carbon
a saturated hydrocarbon is one with..
single bonds only
the functional group is responsible for a molecules…
chemical properties
aliphatic hydrocarbons are…
straight chain or branched cabin hydrocarbons
cyclic hydrocarbons are…
a hydrocarbon with C atoms joined in a ring shape
a homologous series is…
a family of compounds with the same functional group, similar chemical properties and the same general formula
cracking is…
the breaking down of long chained saturated hydrocarbons to form a mixture of shorter chain alkenes and alkanes
catalysts are…
substances that increase the rate of a chemical reaction without undergoing a permanent chemical change
heterogenous catalysts are….
catalysts in a different state to the reactants
homogenous catalyst are…
catalysts that are in the same state as the reactants
the Pi bond is the…
reactive part of a double bond
isomerisation is…
converting straight chain alkanes into branches chain alkanes
reforming is when…
aliphatic hydrocarbons are converted to cyclic hydrocarbons
standard conditions are…
298k
1 atm
conc of 1 moldm3
catalyst poisoning…
when a catalyst no longer works properly
an electrophile is…
an electron pair acceptor
a carbocation is…
an ion with a positively charged carbon atom
addition reactions are..
when two or more molecules react to form a single larger molecule
a polymer is…
a long molecular chain made from smaller molecules (monomers)
monomers are…
small molecules that combine with many other monomers to form a polymer
addition polymerisation is..
reaction is which many monomers containing at least one C=C double bond form long chain polymers
avogadros law states that..
equal volumes of gases at the same temperature and pressure contain equal numbers of molecules
e/z isomerism is…
different groups attached to each C of the C=C may be arranged in space differently because of the restricted rotation of the C=C bond
cis/trans isomerism is…
where there is a non hydrogen and hydrogen atom on each C atom in the C=C
the cis isomerism is also known as..
the Z isomer
trans isomerism is also known as …
the E isomer
the cis (Z) isomer has the H atoms on…
the same side
the trans (E) isomer has the H atoms on….
different sides
biofuels are…
alternative fuels derived from renewable plant and animal materials
molar volume is…
24 mol dm-3
stereoisomers are…
compounds with the same structural formula but with a different arrangement of atoms in space
give the equation for the formation of CO2
C (s) + O2 (g) –> CO2 (g)
the Pi bond is formed..
by…
above and below the place of bonded atoms
by a sideways overlap of p orbitals
