U10 PT- Caleb, Bruno, and Aidan
Equilibrium
Chemical Rates
Reaction rates
The speed at which reactants are converted into products.
Collision Theory
states that when suitable particles of the reactant hit each other, only a certain fraction of the colliisions cause any noticeable or significant chemical change; these successful changes are called effective collisions.
a state in which the forward and reverse reactions balance each other because they take place at equal rates.
Rate Law
the rate law or rate equation for a chemical reaction is an equation that links the reaction rate with the concentrations or pressures of the reactant.
Rate-determining step
the slowest step of a chemical reaction that determines the speed (rate) of the overall reaction proceeds
rate law is expressed as k[A]ˣ[B]ʸ
k is a constant.
[A] and [B] are concentrations of reactants.
exponents x and y are reaction orders.
A reversible reaction is a chemical reaction that can occur in both forward and reverse directions.
All the reactants and products are present at equilibrium
The concentrations of the reactants and products reach constant values and these are called equilibrium concentrations.
Rate of forward reaction is equal to rate of reverse reaction
How to calculate them: Reaction rate is calculated using the formula rate = Δ[C]/Δt, where Δ[C] is the change in product concentration during time period Δt.
Example:
The 3 parts of the Collision Theory
That they must collide with enough energy
That reacting substances must collide
They must collide with the correct orientation.
Le Chatelier's Principle
Increase pressure of system: favors fewer moles of gas.
Decrease pressure of a system: favors more moles of gas.
Decrease concentration of a substance: Shifts towards that substance.
Increase temperature of system: Shifts towards endothermic reaction.
Increase concentration of a substance: shifts away from that substance.
Decrease temperature of a system: Shifts towards exothermic reaction.
Add catalyst: NO SHIFT
Definition:If stress is applied to a system at equilibrium, the system shifts in the direction that relieves the stress.
Changes that Affect Rate.
Surface Area.
Temperature.
Concentration.
increasing the concentration of the reactants will allow for more effective collisions between particles because there are more particles to collide with each other. The rate will increase.
increasing surface area increases reaction speed. More effective collisions can occur and rate increases.
increasing temperature increases the amount of kinetic energy in a reaction. Therefore, more effective collisions can take place between particles and rate will increase.
