KINETICS Flashcards
Under what conditions can a reaction occur
The particles need sufficient energy
To be in the correct orientation
To collide with the correct molecule
Define activation energy
Minimum energy which particles need to collide to start a reaction
Define Emp and where its located on a Maxwell Boltzmann Distribution
The most probable energy
The peak of the curve
where is the total number of particles located on a Maxwell Boltzmann Distribution
Area under the curve
Define molecules that can react and where its located on a Maxwell Boltzmann Distribution
Molecules with sufficient activation energy
Area under the curve past the Ea
Define mean energy and where its located on a Maxwell Boltzmann Distribution
The averaged energy across all molecules
Roughly half way along the curve
Outline features of the Maxwell Boltzmann Distribution
Passes through origin
Very few molecule with little energy
Peak typically toward the left
Never meets the axis
How can a reaction go to completion if a few particles have energy greater than Ea?
Particles can gain energy through collisions
How does increasing the temperature effect the maxwell Boltzmann distribution
Peak moves right
Peak moves lower
More particles above the Ea
Area under curve does not change
How does decreasing the temperature effect the maxwell Boltzmann distribution
Peak moves left
Peak moves up
Less molecules above Ea
Area under curve unchanged
Define rate of reaction
Change in concentration of s substance in a unit of time
Mol dm^-3s^-1
Outline the features of a time-concentration graph
Gradient = rate of reaction
Initial rate is the fastest rate
Concentration of reactants leads to a negative curve
Concentration of products leads to a positive curve
When is 1/time used to calculate the rate of reaction
The amount of the substance is fixed and constant
How does increasing the pressure effect the maxwell Boltzmann distribution
The curve becomes higher
But the shape does not change
How does decreasing the pressure effect the maxwell Boltzmann distribution
The curve lowers
But the shape doesn’t change
