Developing Fuels Flashcards
What does the enthalpy change tell us?
The amount of energy transferred to or from the surrounding in a chemical reaction
What are the standard conditions for enthalpy changes?
25 degrees 100 kPa
What is enthalpy
The internal energy in a system
What is the equation for change in thermal energy?
Q=MCdeltaT
How does spectroscopy work?
Ions dipped in solution and placed under a flame to determine their ions and the way the atoms are held
What happens to electrons when they gain extra energy?
They get excited and move up a shell
What is the energy gap?
It is the space between a level and the amount of energy needed to get to that next level- this is unique for each element
What is the absorption spectra?
White background, black lines
What is a chain isomerism?
The carbon chain has a different arrangement
What is a functional group isomerism?
There are different functional groups in the compound
What is a positional isomerism?
The functional group is in a different position in the chain/molecules
What is stereoisomerism?
The lack of free rotation around a double bond
Why do alkenes have stereoisomers?
They have the lack of free rotation around a double bond
What is internal energy?
The sum of the kinetic and potential energies of the particles making up a substance
Define enthalpy change of neutralisation
When one mole of hydrogen ions react with one mole of NaOH ions to form one mole of water in standard states and conditions
Define enthalpy change of combustion
When one mole of a substance is completely burnt in oxygen in standard states and conditions
Define enthalpy change of formation
A mole of a compound is formed from its elements in standard states and conditions
What is the equation for enthalpy?
Enthalpy = pressure x volume + Energy
Define enthalpy change of reaction
When the mole quantities in the reaction react together in standard states and conditions
State Hess’ law.
The enthalpy change for a reaction is dependant on any intermediate stages
Define bond enthalpy
It is the energy needed to break a particular bond
