Section 3 Developing Fuels Flashcards
(21 cards)
standard conditions gas volume equation?
Moles = Volume (dm3) / 24
Ideal gas equation?
pV = nRT
p =pressure in pascals
V= volume in m3
n= number of moles
R= gas constant (8.314)
T= temperature (K)
what is enthalpy change of reaction equal to?
Total energy absorbed to breaks bonds - total energy released to make bonds
Define
1. Standard enthalpy change of reaction.
- Standard enthalpy change of formation.
- Standard enthalpy change of combustion.
- Enthalpy change when the reaction occurs in the molar quantities shown in the chemical equation, under standard conditions.
- Enthalpy change when one mole of a compound is formed from its elements under standard conditions.
- Enthalpy change one mole of a substance is burned completely in O2, under standard conditions.
define standard enthalpy change of neutralisation.
Enthalpy change when an acid and alkali react together under standard conditions, to form 1 mole of water.
Enthalpy change formula?
q= mcΔT
q= heat gained or lost in joules
m= mass of solution (g)
c= specific heat capacity of water (4.18)
ΔT= change in temperature of solution (K)
describe heterogeneous catalysis in 4 steps
- Adsorption of reactant molecules onto catalyst surface.
- Bonds in reactant molecules weaken and break.
- New bonds form.
- New molecules desorp from catalyst.
E (trans)/ Z (cis) isomerism
E: Hs across double bond.
Z: When Hs both above or below double bond.
monomer and polymer of ethene
H H
\ /
C = C
/ \
H H
H H
\ /
[ C - C ]n
/ \
H H
test for unsaturation (double bonds)
Add bromine water and shake. Solution will change form orange to colourless if carbon double bonds are present.
What is an electrophile?
Species that accepts electron pair to form bonds with nucleophiles.
Proof of the electrophilic addition mechanism?
If Cl- is added to ethene and bromine mixture, you will get some CH2BrCH2Cl.
This is evidence for mechanism because once ethene has reacted to form carbocation, it can react with chloride and bromide ions.
CO2
Formed when organic compounds are burned completely.
Absorbs infrared radiation, contributing to enhanced greenhouse effect/global warming.
CO
Formed when inorganic compounds burn incompletely when there’s not enough oxygen.
Poisonous as able to bind to haemoglobin molecules in red blood cells due to similar structure to oxygen. This causes suffocation.
Unburnt hydrocarbons and oxides of nitrogen.
oxides of nitrogen produced when high pressure and temperature in a car engine cause the nitrogen and oxygen in the air to react.
The hydrocarbons and nitrogen oxides react in sunlight to form ground level ozone. Which is a component of photochemical smog.
SO2
react with oxygen in the atmosphere to form sulfur trioxide. This dissolves in moisture to form sulfuric acid - acid rain.
This corrodes buildings, kills fish in rivers and destroys trees and vegetation.
Particulates
can settle in lungs, causing irritation of airways and reduced lung function.
Also contribute to cardiovascular problems.
what can be done to reduce pollution?
Government legislation
New vehicles not allowed to pollute over a certain level.
Governments can tax pollution more highly. e.g. raise fuel taxes
Changes in individual behaviour e.g. car sharing
wind, solar, and wave power
Renewable
Carbon neutral-doesn’t contribute to global warming.
Not always reliable as reliant on certain weather conditions.
would take vast numbers to replace energy currently supplied by fossil fuels.
Biofuels e.g. bioethanol, biodiesel and biogas
carbon neutral- do not contribute to global warming as absorb as much CO2 being grown as give off being burnt.
Can be made from waste that would otherwise go to landfill.
Petrol car engines would have to be modified to use fuels with high ethanol concentrations.
Hydrogen as a fuel
Water is only waste product
Can be obtained from seawater but takes energy to extract.
Difficult to transport as has to be liquefied and is highly flammable.
