Unit 1: Section 5: Kinetics Flashcards
What is collision theory
Two particles won’t react with each other unless they are facing in the right direction and they are colliding with at least a certain minimum amount of kinetic energy
What is activation energy
The minimum amount of kinetic energy particles need to react
What are the Maxell-Boltzmann distributions
Some molecules in a substance will have lots of kinetic energy, some will have a low amount of kinetic energy but most will have a moderate amount of kinetic energy
Describe what the Maxell-Boltzmann distribution model looks like on a graph
Sharp increase in y in the beginning
The peak of the curve represents the most likely kinetic energy of any single molecule
The mean energy of all the molecules is slightly to the right to the peak
Most molecules operate between these two points
Then the graph gradually dips and levels out a small number of molecules
What does the area under the Maxell-Boltzman distribution curve represent
The amount of molecules in a substance
What does increasing the temperature of a reaction do to the Maxell-Boltzmann distribution curve
It shifts it to the right
What does increasing the concentration of molecules in a reaction do to the Maxell-Boltzmann distribution curve
It increases the peak of the curve
What does a catalyst do
Provides an alternative reaction pathway that has a lower activation energy
What catalyst is used in tha Haber-Bosch process
An iron catalyst
How does a catalyst affect the Maxell-Boltzmann distribution curve
It does’nt effect it because the same out of energy is present but theres just an alternative reaction pathway
What is the reaction rate
The change in the amount of a reactant or product over time
What is the formula for the rate of reaction
Rate of reaction = Amount of reactant used or product formed/time
What are the three ways to follow a reaction to find out the rate of reaction
The change in mass
Time taken for precipitate to form
Gas volume
Explain how to measure the rate of reaction using the time taken for a precipitate to form
You can use this method when product’s a precipitate that clouds a solution
Stand conical flask on top of white tile with a black cross on it
Add fixed volumes of reactant solutions to the flask and start a stopwatch and the stop the timer when the mark isn’t visible
Explain how to measure the rate of reaction using the the change in mass
When the product is a gas, its rate of formation can be measured using a mass balance
Put conical flask with reactants on a balance to measure the mass
When the reaction starts record the mass at regular intervals into a table with time and mass as the two variables
The reaction stops when the mass balance stops decreasing
