- Spontaneous reactions: reactions that will happen but we cant tell when or how fast
- Kinetics: the study of the rates of a chemical reaction
- Can determine the coefficients of the chemical equation when given graph of concentration vs time by doing:
○ The rate of disappearance of A is equal to the rate of appearance of B and ½ the rate of appearance of C
○ To determine which reactant will be consumed quicker → look at balanced equation
Factors that Affect Reaction Rates
- According to the collision theory, the rate of a reaction is influenced by anything that affects the number or force of collisions
○ Increase collisions = increase rate
- Reactant concentration
○ Increasing concentration causes an increase in the frequency of collisions which increases reaction rates (except for zero-order reactions)
- Increasing temperature: increasing the temp increases the frequency of collisions and the avg KE of the reactants, so more will meet the minimum Ea and collide to form products
○ Increase temperature = increases number of successful collisions
- Pressure: For reactions involving gases, increasing pressure increases the collisions between reactants,
- Particle size and increasing surface area
○ The smaller the particle size with more sides = the larger the surface area
○ Increase surface area (ex: stirring, grinding) → more collisions
- Catalysts: A catalyst will change the value of K because the activation energy changes
○ The value of the rate constant is also dependent on the activation energy
- Inhibitor: a substance that decreases the rate of a reaction by increasing Ea