Kinetics Flashcards
What is a reaction rate?
Change in concentration of reactant or product over time
Name the 2 conditions needed for particles to react with one another when they collide
- Collide with enough minimum kinetics energy
- Collide in the right direction facing each other
What is meant by activation energy?
Minimum amount of energy required for a reaction to occur
Why do particles need a minimum amount of kinetic energy for them to react?
Break bonds and start reaction
What does a Maxwell-Boltzmann distribution show?
Number of molecules in gas with different kinetic energies
Draw a Maxwell–Boltzmann distribution
Y axis = number of molecules
X axis = kinetic energy
Peak, start from 0,0 , asymptote
What does the peak show
The mode - most molecules are moving at this speed
What does the slant on the right of the peak show
Mean ( average )
What area of the curve show that molecules can react
Asymptote but which shows the molecules that can only rest as they have more the activation energy
What is the area under a Maxwell–Boltzmann distribution curve equal to?
Total number of molecules
Why does the Maxwell–Boltzmann distribution curve start at (0,0)?
Because no molecules have 0 energy
Describe the effect of temperature on reaction rate
Increased temperature = more kinetic energy = move faster and more frequent collisions in a given time as more number of molecules are able to react
Increase in temperature on Maxwell–Boltzmann distribution curve
Moves to the right and bigger asymptote section , smaller peak as area under graph stays the same
Why does a small increase in temperature create a large increase in reaction rate?
More molecules have energy greater than activation energy so far more successful collisions per second
Decrease in temperature on Maxwell–Boltzmann distribution curve
Moves to left with a higher peak and smaller asymptote space
