Unit 3 AoS 1 - Energy and Fuels Flashcards
What is energy?
The ability to do work, the mover of substances
What is a fuel?
A material burned to produce heat or energy
What is a fossil fuel?
A fuel sourced from the earth that takes thousands of years to form. Is non renewable.
What is a biofuel?
A renewable source of energy used as a substitute for common fossil fuels. is prodiced from waste plant materials, allowing for it to be replenished in a short period of time.
What is an exothermic reaction?
A reaction that releases more energy than supplied, producing heat. Has a negative H value.
What is an endothermic reaction?
A reaction that releases less energy than is supplied, becoming cold. Has a positive H value
What is the activation energy?
The amount of energy needed to initiate the reaction
What does a catalyst do to reactions?
Offers an alternative reaction pathway that lowers activation energy, and speeding up the reaction.
What is the unit energy is measured in?
Joules (J)
What indicates a thermochemical equation?
When the heat term is included
What are the products of the complete combustion of a hydrocarbon?
CO2 and H2O
What are the products of the incomplete combustion of hydrocarbon?
CO2, H2O, CO, and/or C
What are the properties of all gasses?
They have low densities, fill any container completely and uniformly, are compressible, have uniform pressure, and diffuse easily.
What are the factors of Standard Laboratory Coniditions (SLC)?
Temp: 25*C (298 K) Pressure: 100kPa
What is the molar volume of gasses at SLC?
24.8L
What is the general gas equation?
P(ressure in kPa) x V(olume in Litres) = n(moles) x R(8.31) x T(emp in Kelvin)
What is Gay Lussac’s Law?
When gasses react, the volume in which they react and the volume of the gaseous products are in ratio of simple whole numbers (moles coefficients)
What is a REDOX reaction?
Reduction-oxidation reactions, tranferance of elections
What is the common expression to remember REDOX reactions?
OIL RIG: Oxidation is loss, reduction is gain
What is a Galvanic Cell?
A spontaneous REDOX reaction that generates electrical energy from chemical energy
What are the components of a galvanic cell?
Electrodes, electrolytes, salt bridge
What does oxidation occur?
At the annode (AN OX)
Where does reduction occur?
At the cathode (RED CAT)
How are hald-equations balanced?
- Balance elements other than hydrogen and Oxygen
- Balance oxygen by adding water
- balance hydrogen atoms with H+ ions
- balance electrical charge using electron
How to determine the annode and cathode using the electrochemical series
Find where each half-cell is on the electrochemical series. The highest one is the least reactive and is reduce, whilst the lowest one is the most reactive and is oxidised. draw backward C shape from top to bottom
What is the standard cell potential equation?
Ecell = Eoxidant - Ereductant
What are fuel cells?
Electrochemical devices that convert chemical energy into electrical energy and heat. Are spontaneous
what are the common design feature of fuel cells?
Have prous electrodes for gaseous reactants and have a continous supply of reactants
What are certain qualities of fuel cells that must be considered?
Safety, fuel supply and sotrage, production of greenhouse gases and applications.
