Developing Fuels Flashcards
Sigma bond is…
a type of covalent bond which forms when s-orbitals overlap
Pi bond is…
a type of covalent bond which form when p-orbitals overlap . Appear above and below the bonding C atoms
Hess Law’s is
the enthalpy change of a reaction is independent of the pathway taken between intial and final states.
Enthalpy of neutralisation is..
when one mole of OH- reacts with H+ to form one mole of water under standard conditions
Define catalyst
A substance that speeds uo the rate of reaction by finding an alternative pathway with a lower activation energy and is reproduced at the end of the reaction.
Heterogeneous catalyst is
when the catalyst has a different physical state to the product
Proof of incomplete combustion is…
when CO or C is produced
What is a hydrogen fuel cell?
An electrochemical cell that converts the chemical energy of hydrogen and oxygen into electricity through redox reactions
Stereoisomers are….
compounds with the same strucutral formula but different arrangement of atoms in space.
What is E/Z isomerism
A type of stereoisomerism caused by the restricted rotation of pi bonds.
E/Z isomers properties
E isomers = functional group on opposite sides, so is non polar, low mp/bp, weak bonds
Z isomers= functional group on the same side, polar, high mp/bp, strong bonds
Define electronegativity
The relative ability of an atom to attract a pair of electrons in a covalent bond
Ideal gas equations
pV = nRT
What is calorimetry
An experimental method for finding an enthalpy change by measuring temperature change over time as a reaction occurs.
F.UC.D
Formation Up Combustion Down
What is catenation
When carbon forms strong covalent bonds with itself to give chains and rings of its atom
Features of alkanes
Saturated hydrocarbons
General formula is CnH2n+2
Suffix = -ane
Physical properties change gradually in the series as the number of carbon atoms increases
How to test for alkenes?
Add bromine water and shake turns from orange/brown to colourless
How do heterogeneous catalysts work
- Reactants adsorb to catalyst surface
- Reactant bonds break
- New bonds form to form new product
- Product diffuses from catalyst surface
Equations for catalytic convertors in cars converting harmful gases into less harmful ones
2NO +2CO —-> N2 + 2CO2
What is octane number?
The tendency of a fuel to auto-ignite is measured using octane numbers
What does a high octane number
Low tendency to auto-ignite
Properties of alkenes
CnH2n
Unsaturated
Fewer Hydrogen bonds
Conditions required for hydrogenation
Platinum catalyst at room temp/pressure
or
Nickel catalyst at high temperature and pressure
Conditions required for hydration
High temperature, pressure and phosphoric acid or conc. sulfuric acid
What is position isomer?
The functional group is on a different carbon atom.
What is addition polymerisation?
Monomers are joined together to form polymers and forms only one product is formed
What are co-polymers made from?
Polymers made from 2 different monomers
What causes global warming , the effect and solution?
CO2 causes global warming, it causes ice caps to melt and sea levels to rise and tropical diseases. Use alternative fuels
What causes acid rain , the effect and solution?
SO2 causes acid rain , it kills trees and aquatic life. Damages limestone statues and buildings. We can solve it by removing sulphur from fuel cataltic convertors
What causes global dimming , the effect and solution?
Carbon particulate causes global dimming which respiratory problems , lung cancer and heart attack. We can solve this by well serviced engines.
Advantages of biodiesel
Made from waste oil rather than using fossil fuel based oil
Carbon neutral
Contains virtually no sulfur, so reduces oxids of sulfur in emissions
Produces less particulates, carbon monoxide and hydrocarbons than petrol and diesel.
Disadvantages of biodiesel
Produces more nitrogen oxides than conventional fossil fuels
Advantages of hydrogen
Renewable can can be made by electrolysis of water
Can be stored and sent down pipelines like methane
Can be used in internal combustion engines or in a fuel cell to generate electricity
Produces no carbon dioxide, carbon monoxide or hydrocarbons when burnt
Disadvantages of hydrogen
Production from water is dependent on the use of electricity from fossil fuel power stations, less energy dense than petrol and oxides of nitrogen are still produced.
How do fuel cells work?
Fuel cells convert the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent in an electrochemical cell.
