controlling the rate 3.2 Flashcards
what effects the rate of reaction
temperature, concentration, particle size/surface area, catalyst, pressure and collision theory
collision theory
in order for a successful reaction to occur, particles must collide with enough energy and the right geometry
particle size
the smaller the particle size the faster the reaction, this is due to increased surface area
concentration
the higher the concentration the faster the reaction, this is due to increased number of particles available to react
temperature
increasing the temperature of a reaction increases the kinetic energy of the particle, this results in more successful collisions and increases the rate of reaction
catalyst nat5
a chemical that speeds up a chemical reaction but remains unchanged
catalyst higher
provides an alternative pathway to the reaction which reduces the energy required for a successful collision
activation energy
(Ea) is the minimum energy required by colliding particles to form an activated complex
activated complex
an unstable arrangement of atoms formed at the maximum of potential energy barrier
what do you use to measure rate of reaction
loss of mass (measures the mass lost during the reaction) or a gas syringe (measures the volume of gas produced)
what is enthalpy
the measure of the chemical energy stored in a substance
what is the enthalpy change (deltaH) of a reaction
the difference in chemical energy of the reactants and the products
when the enthalpy change is negative…
the reaction is exothermic (releases heat energy)
when the enthalpy change is positive…
the reaction is endothermic (takes in heat energy)
how to calculate activation energy (Ea)
peak of reaction - reactants
