120 likes | 239 Vues
Understanding the factors that affect the rates of chemical reactions is crucial in chemistry. Key elements include temperature, which increases particle motion and collision frequency; surface area, where finely ground substances react faster due to more exposed atoms; concentration, with higher particle density enhancing reaction likelihood; and pressure, which compresses gases and boosts interaction. Catalysts play a critical role as they lower activation energy, providing alternative pathways for reactions without being consumed. Explore these factors to grasp reaction dynamics better.
E N D
Reactions occur because two reactant atoms, ions, or molecules collide. Reactions only occur with favorable collisions Anything that increases the chance of a collision will increase the rate of a reaction.
Temperature As temp increases, particle motion speeds up. Faster particles are more likely to collide. Hi temp reacts faster. Cooling down reduces the reaction rate.
Surface area Only surface atoms react. The more a substance is ground up, the more surface atoms it has. Ground up substances react faster than chunks,
Concentration More relevant for liquids and aqueous solutions. More particles in an area will increase chances of a reaction. Higher concentration increases reaction rate. Adding water will lower the concentration and can quench a reaction.
Pressure Applicable to gases Hi pressure forces reactant particles together and increases reaction rate.
Catalyst Does not participate in the reaction: neither a product nor a reactant. Provides an alternate pathway for the reaction to take, one with a lower energy requirement.
Activation energy EA The amount of energy required to make a reaction go. The energy required to break the bonds of the reactants.
Energy descriptions Exothermic: releases energy. Like a fire Endothermic: absorbs energy: like a cold pack.
Potential energy diagrams tutorial http://www.kentchemistry.com/links/Kinetics/PEDiagrams.htm