5.1 Reaction Rates

Can reaction rates be negative?

No

The rate at which an amount of reactants is converted to products per time:

Kinetics

What are the rates of change of reactant and product concentrations determined by?

Stoichiometry in the balanced chemical equation

What is the rate of reaction influenced by?

Reactant concentrations, temperature, surface area, catalysts, and other environmental factors

What are the conditions for successful collisions?

Collisions should have energy equal or greater than activation energy, and reactant molecules should have proper orientation

The minimum amount of energy required to start a reaction:

Activation energy

How does frequency of successful collisions affect rate of reaction?

Greater the frequency, higher the rate

According to collision theory, what must happen for products to be formed in a chemical reaction?

Reactant particles must undergo successful collisions

Which factors increase amount of product?

Higher concentration of reactants

Which factors do not increase amount of product but increase rate of reaction?

Higher temperature, higher pressure, lower volume, higher surface area, catalyst

How does higher temperature increase rate of reaction?

Higher kinetic energy → more particles move faster and have energy more than activation energy → higher frequency of successful collisions → higher rate of reaction

How does increasing concentration increase rate of reaction?

More moles of reactants → higher frequency of successful collisions → higher rate of reaction

How does increasing pressure increase rate of reaction?

Molecules come closer → higher frequency of successful collisions → higher rate of reaction

How does decreasing volume increase rate of reaction?

Molecules come closer → higher frequency of successful collisions → higher rate of reaction

Factors that increase rate of reaction:

Increasing temperature, increasing concentration of reactants, increasing pressure, decreasing volume, catalyst, decreasing size of reactants

How does decreasing size of reactants increase rate of reaction?

Increases surface area → more sides collide with each other → higher frequency of successful collisions → higher rate of reaction