Factors that Influence the Rate 2.2.3, 2.2.4, 2.2.5 Flashcards
What are the five factors that influence the rate of a reaction?
- Temperature
- Concentration
- Pressure
- Surface area
- Addition of a catalyst
Temperature vs Rate
As temperature increases, the rate increases.
The kinetic energy increases. Therefore the number of collisions with the necessary Ea increases.
How the maxwells boltzmann graph changes when the temperature increases.
The total particles under the curve does not change but the curve flattens a bit and shifts right, making there be more particles under the same Ea value.
Concentration vs Rate
As concentration increases, the rate increases. More particles in same space. This is why rate decreases as reactants are used up.
Pressure vs rate
Only applies to gases, as pressure increases, the rate increases. Same particles for less space, causing more collisions.
Surface area vs rate
By increasing surface area, the rate increases as more molecules are exposed per volume (for solids). Powder reacts faster than large lumps.
What is a catalyst?
A catalyst is a substance that increases the rate of a chemical reaction without itself undergoing a permanent chemical change
How does a catalyst work?
It provides an alternate route for the reaction that has a lower activation energy.
Transition Elements as Heterogeneous Catalysts
- Fe in the Haber process
- Ni in the hydrogenation of margarine
- Pd and Pt in catalytic converters
- MnO2 in the decamp of H2O2
- V2O5 in the contact process
Transition Elements as Homogeneous Catalysts
- Fe in haemoglobin
- Co in vitamin b12
