Kinetics 5 Flashcards
collision theory
for a reaction to take place between two particles, they must collide with enough energy to break bonds
factors that affect the rate of a chemical reaction
increasing the temperature
increases the speed of the molecules which in turn increases the energy and number of collisions
factors that affect the rate of a chemical reaction
increasing the concentration of a solution
more particles are present in a given volume then collisions are more likely and the reaction rate would be faster. however, as a reaction proceeds, the reactants are used up and their concentration falls. so, in most reactions, the rate of reaction drops as the collisions are more likely
factors that affect the rate of a chemical reaction
increasing the pressure of a gas reaction
there are more molecules or atoms in a given volume so collisions are more likely
factors that affect the rate of a chemical reaction
increasing the surface area of solid reactants
greater the total surface area, more of the particles are available to collide with molecules in a gas or liquid
factors that affect the rate of a chemical reaction
using a catalyst
a catalyst is a substance that can change the rate of chemical reaction without being chemically changed itself
maxwell-Boltzmann distribution
- no particles has zero energy
- most particles have intermediate energies
- a few have very high energies
activation energy
reaction to take place, a collision between particles must have enough energy to start breaking bonds.
the area under the line represents the number of particles with enough energy to react.
effect of temperature on the rate of reaction
at high temperature, the peak of the curve is lower and moves to the right. the number of particles with very high energy increases.
catalysts
provide a different pathway for the reaction, one with a lower activation energy
Don’t get used up in the reaction
(A catalyst is a substance that increases the rate of a chemical reaction without being changed in chemical composition or amount)
what catalyst does the Haber process use ( and uses)
- iron
- making fertilisers
catalyst and uses of
4NH3 + 5O2 — 4NO +6H20 (nitric acid)
- platinum and nickel
- making fertilisers and explosives
catalyst and uses of
hydrogenation
- nickel
- margarine
catalyst and uses of cracking hydrocarbon chains from crude oil
- aluminium oxide and silicon dioxide zeolite
- making petrol
catalyst and uses of the catalytic converter reactions in car exhausts
- platinum and rhodium
- removing polluting gases
