6.2 & 6.3 Factors Affecting Reaction Rates
The chemical nature of a pure substance is what gives it its chemical properties.
For example: sodium is very reactive and oxidizes (loses electrons) quickly. With respect to sodium, iron has a slow oxidation reaction.
Increasing the likelihood of 2 of the reactants colliding together and reacting.
Surface area affects the ability of the reactants to come into contact with each other.
Reactions are most often carried out in liquid solutions or in the gaseous phase, which have higher surface area.
Almost all chemical reactions occur faster at higher temperature.
Example – polaroid camera’s instant pictures develops quicker in warmer weather.
Rate of the reaction tends to double with every increase of 10 oC.
Catalysts are chemical which speed up the rate of reaction but are not consumed by the reaction. There are two types:
Heterogenous catalysts: reactants and catalyst are in different physical states
Ex: production of polyethylene is sped up with a metal catalyst. An ethene molecule binds to the metal catalyst, breaking the double bond and allowing another ethene molecule to bond.
Homogeneous catalyst: reactants and catalyst are in the same physical state (aq or g)
Ex: biocatalysts or enzymes are in the aqueous state, as are most of their reactants. Lactose for example is an enzyme that helps in the digestion of milk.
Reactions occur when
Reactants collide with proper orientation
Reactants collide with enough kinetic energy
Minimum energy of reactants for a reaction to occur
Overcome electrostatic force of repulsion
Break reactant bonds
The KINETIC energy of the collision must be GREATER than the POTENTIAL energy of the bonds
The chemical nature of a pure substance is what gives it its chemical properties.
For example: sodium is very reactive and oxidizes (loses electrons) quickly. With respect to sodium, iron has a slow oxidation reaction.
Increasing the likelihood of 2 of the reactants colliding together and reacting.
Surface area affects the ability of the reactants to come into contact with each other.
Reactions are most often carried out in liquid solutions or in the gaseous phase, which have higher surface area.
Almost all chemical reactions occur faster at higher temperature.
Example – polaroid camera’s instant pictures develops quicker in warmer weather.
Rate of the reaction tends to double with every increase of 10 oC.
Catalysts are chemical which speed up the rate of reaction but are not consumed by the reaction. There are two types:
Heterogenous catalysts: reactants and catalyst are in different physical states
Ex: production of polyethylene is sped up with a metal catalyst. An ethene molecule binds to the metal catalyst, breaking the double bond and allowing another ethene molecule to bond.
Homogeneous catalyst: reactants and catalyst are in the same physical state (aq or g)
Ex: biocatalysts or enzymes are in the aqueous state, as are most of their reactants. Lactose for example is an enzyme that helps in the digestion of milk.
Reactions occur when
Reactants collide with proper orientation
Reactants collide with enough kinetic energy
Minimum energy of reactants for a reaction to occur
Overcome electrostatic force of repulsion
Break reactant bonds
The KINETIC energy of the collision must be GREATER than the POTENTIAL energy of the bonds