Kinetics Flashcards
chap 5
Collision theory
2 particles must collide w enough energy for bonds to break and must collide at the right orientation, in order to react
Transition state
the state when some bonds are in the process of being made and some are in the process of being broken
What effect does temp have on ROR? When temp increases, by how much does ROR increase?
- ^^ speed of particles
- ^^ energy
- ^^ collisions
rate doubles temp increase
What effect does catalyst have on ROR?
- dec Ea
- by providing an alternative mechanism w a dec Ea
What effect does surface area have on ROR?
- ^^ more exposure of particles
- ^^ more sites for reaction available
- ^^ collisions
What effect does concentration and pressure have on ROR?
- ^^ atoms in given volume
- ^^ collisions
What is a maxwell-boltzmann curve and what 2 things does it show? When does the curve shift? What does it never touch?
- A graph of energy of molecules against number of molecules, showing Ea and Emp
- When temp inc or dec
- The x axis
Heat change formula (q)
Heat change (J)= mass (g) x SHC (Jg-1K-1) x temp change (K)
Why does theoretical heat change not always = actual heat change? (4)
- heat loss to surroundings
- heat absorbed by container
- incomplete combustion
- evaporation (when fuel is volatile)
Enthalpy formula
Enthalpy= Energy/moles
Enthalpy definition
Measure of the heat content of a substance
Enthalpy change definition
Change in heat content at constant pressure
