https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:reaction-rates-and-equilibrium/x2613d8165d88df5e:reaction-rates/v/collision-theory 2021-01-30T09:09:56Z Collision theory Collision theory states that molecules must collide to react. For most reactions, however, only a small fraction of collisions produce a reaction. In order for a collision to be successful, the reactant molecules must collide both with sufficient energy to overcome the activation energy barrier and in the proper orientation to form any new bonds in the products. Jay video https://cdn.kastatic.org/googleusercontent/KVNzRM6P5K59aYcHOyMgVFrq8GKsRUK3rh9_mblSqnd9RyYTNRU8NqV5R1gpqVQK05Dgl4z7KCfshabcgG_igWvr1A Collision theory Collision theory states that molecules must collide to react. For most reactions, however, only a small fraction of collisions produce a reaction. In order for a collision to be successful, the reactant molecules must collide both with sufficient energy to overcome the activation energy barrier and in the proper orientation to form any new bonds in the products. https://cdn.kastatic.org/ka-youtube-converted/1iAxhc6EflI.mp4/1iAxhc6EflI.mp4 528 Rate of reaction https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:reaction-rates-and-equilibrium/x2613d8165d88df5e:reaction-rates/e/understand-collision-theory 2026-03-11T05:00:37.141016324Z Understand: collision theory Check your understanding of collision theory in this set of free practice questions. Allen Ruch exercise https://www.khanacademy.org/science/ap-chemistry-beta/x2eef969c74e0d802:kinetics/x2eef969c74e0d802:reaction-rates/v/rate-of-reaction 2021-01-30T09:10:01Z Introduction to reaction rates The rate of a chemical reaction is defined as the rate of change in concentration of a reactant or product divided by its coefficient from the balanced equation. A negative sign is used with rates of change of reactants and a positive sign with those of products, ensuring that the reaction rate is always a positive quantity. In most cases, concentration is measured in moles per liter and time in seconds, resulting in units of M/s for the reaction rate. Jay video https://cdn.kastatic.org/googleusercontent/cpSAiTKbHANKHeK8VXNbBhHsnmUEUQcPx7y9Bs_45FuGkktvAfGRpuqre4MErFJGvMJVWmKF9fwHow0hA6sF7NJ0 Introduction to reaction rates The rate of a chemical reaction is defined as the rate of change in concentration of a reactant or product divided by its coefficient from the balanced equation. A negative sign is used with rates of change of reactants and a positive sign with those of products, ensuring that the reaction rate is always a positive quantity. In most cases, concentration is measured in moles per liter and time in seconds, resulting in units of M/s for the reaction rate. https://cdn.kastatic.org/ka-youtube-converted/8wIodo1HD4Y.mp4/8wIodo1HD4Y.mp4 554 Rate of reaction https://www.khanacademy.org/science/biology/energy-and-enzymes/introduction-to-enzymes/v/introduction-to-kinetics 2024-02-03T14:54:13.458936091Z Introduction to kinetics Kinetics is the study of reaction rates and how they are affected. Many factors, such as concentration, pressure, temperature, and enzyme activity, can impact the rate of a reaction. For example, a molecule's kinetic energy is directly proportional to its temperature, so increasing the temperature will result in an increase in reaction rate. Sal Khan video https://cdn.kastatic.org/googleusercontent/DuVcx4Fhk9hZy4HgCu0TSi5H29WWYfUhgmiOjK7jw7-cUcQ-t9fg7_mJAw_3iTrwIMMoUa6PxaPkCwFFDbLyKScY Introduction to kinetics Kinetics is the study of reaction rates and how they are affected. Many factors, such as concentration, pressure, temperature, and enzyme activity, can impact the rate of a reaction. For example, a molecule's kinetic energy is directly proportional to its temperature, so increasing the temperature will result in an increase in reaction rate. https://cdn.kastatic.org/ka-youtube-converted/__zy-oOLPug.mp4/__zy-oOLPug.mp4 927 Rate of reaction https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:reaction-rates-and-equilibrium/x2613d8165d88df5e:reaction-rates/v/factors-affecting-reaction-rates 2022-10-05T02:43:18.611402953Z Factors affecting reaction rates The rate of a chemical reaction is influenced by many different factors, including reactant concentration, surface area, temperature, and catalysts. In general, increasing the concentration of a reactant in solution, increasing the surface area of a solid reactant, and increasing the temperature of the reaction system will all increase the rate of a reaction. A reaction can also be sped up by adding a catalyst to the reaction mixture. Jay video https://cdn.kastatic.org/ka_thumbnails_cache/b2fb2453-05c7-482e-98ee-0bb9abf02353_1280_720_base.png Factors affecting reaction rates The rate of a chemical reaction is influenced by many different factors, including reactant concentration, surface area, temperature, and catalysts. In general, increasing the concentration of a reactant in solution, increasing the surface area of a solid reactant, and increasing the temperature of the reaction system will all increase the rate of a reaction. A reaction can also be sped up by adding a catalyst to the reaction mixture. https://cdn.kastatic.org/ka-youtube-converted/CoNHV7786Hg.mp4/CoNHV7786Hg.mp4 329 Rate of reaction https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:reaction-rates-and-equilibrium/x2613d8165d88df5e:activity-why-does-food-in-a-refrigerator-stay-fresh-for-longer/a/activity-why-does-food-in-a-refrigerator-stay-fresh-for-longer 2026-01-14T23:20:41.344464701Z Activity: Why does food in a refrigerator stay fresh for longer? Make science come alive in your classroom with this free hands-on activity aligned to high school standards. article https://www.khanacademy.org/science/ap-chemistry-beta/x2eef969c74e0d802:kinetics/x2eef969c74e0d802:reaction-rates/e/reaction-rates 2021-04-29T08:02:44Z Reaction rates Check your understanding of reaction rates in this set of free practice questions designed for AP Chemistry students. exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:reaction-rates-and-equilibrium/x2613d8165d88df5e:reaction-rates/e/understand-factors-affecting-reaction-rates 2025-11-10T23:10:47.553327376Z Understand: factors affecting reaction rates Check your understanding of factors affecting reaction rates in this set of free practice questions. Allen Ruch exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:reaction-rates-and-equilibrium/x2613d8165d88df5e:reaction-rates/e/apply-factors-affecting-reaction-rates 2026-03-11T05:00:37.141016324Z Apply: factors affecting reaction rates Apply your understanding of factors affecting reaction rates in this set of free practice questions. Allen Ruch exercise