Unit 5: Topic 1 - Reaction Rates Flashcards
What is kinetics?
Kinetics is the branch of chemistry that studies the rate of a reaction. We find this by solving for the change in concentration over the change in time. As time goes on, the concentration of reactants decreases while the concentration of products increases.
What does the stoichiometry of a chemical equation say about the reaction rates?
The coefficient of a balanced chemical equation tells us about the rate of change of reactants and products. Here is an example.
Based on the curve, the concentration of H2 is decreasing faster than the concentration of N2. This is because H2 has a coefficient of three while N2 has a coefficient of one. This means more moles of H2 are needed for the reaction thus H2 will be consumed THREE times faster than N2. Since NH3 has a coefficient of 2, it is increasing TWICE as fast as N2 is decreasing.
What are some factors that can affect reaction rates?
Factors like reactant concentrations, temperature, surface area, and catalyst affect the rate of reaction.
1. Increasing the reactant concentration will increase the number of collisions that are needed in order for the reaction to occur thus increasing the reaction rate.
2. Raising the temperature means more collisions and faster reaction rate.
3. With more surface area, more particles are exposed to the reactant thus increasing the reaction rate.
4. A catalyst speeds up chemical reactions by lowering the activation energy (more on this later on)
