Kinetics Flashcards
What is the equation for rate
Rate = ∆C/t (∆C being change in concentration, t being time)
What is activation energy
Activation energy is the minimum energy required for a reaction to occur
What is a catalyst
A substance that increases the rate of a reaction without being used up by providing an alternative pathway for the reaction of lower activation energy
What 4 factors affect the rate of a reaction
Temperature
Concentration/Pressure
Surface area
Presence of a catalyst
Explain how increasing temperature increases the rate of reaction
-Molecules have more kinetic energy
-More molecules have E≥Ea
-Frequency of collisions increases
-More successful collisions in a given time
Explain how increasing concentration/pressure increases the rate of reaction
-More molecules in a given volume
- Frequency of collisions increases
- More successful collisions in a given time
(Collision energy remains the same)
Explain how increasing surface area increases the rate of reaction
-More solid is exposed giving more contact with reagent
-Collision frequency increases
-More successful collisions in a given time
(Collision energy remains the same)
Explain how adding a catalyst increases the rate of reaction
-Provides an alternative route of lower activation energy
-More particles will have the new, lower activation energy (More molecules have E≥Ea)
-More collisions in a given time
(Frequency and energy if collisions remain the same)
Explain why the rate of a reaction decreases over time
-Concentration of reactant molecules decreases
-Lower collision frequency
-Less successful collisions in a given time
-Hence rate of reaction is slower
How does increasing temperature affect a concentration time graph (draw it)
The point where the reaction stops on the product line shifts to the left of the original (same concentration)
How does halving the concentration of a reactant affect a concentration time graph
The point where the reaction stops on the product line shifts to the right of the original (with half the concentration
Draw a concentration time graph of product against reactant
Google/notes
What is on the X and Y axis of a Maxwell-Boltzmann distribution (MBD)
X - Energy
Y- Number of particles
Where does the mean energy of particles on a MBD lie in comparison to the peak
The mean energy of particles always lies to the right of the peak
What does the peak on a MBD represent
The most probable energy
