kinetics Flashcards
how can a reaction occur successfully
particles need to collide with energy greater than or equal to the activation energy
what does the total area under a maxwell-boltzmann curve represent
the total number of molecules in the sample.
what is the effect of temperature on the rate of reaction
heating the substance provides the particles with more kinetic energy so they move faster. this causes collisions to occur more often and with greater energy. more collisions will have energy greater than the activation energy so the rate of reaction will increase.
what is the effect of temperature on the maxwell-boltzmann distribution
the curve shifts to right and lowers slightly. a greater proportion of molecules have energy greater than or equal to the activation energy. the area under the curve is the same
what is the effect of concentration and pressure on the rate of reaction
when the concentration of the sample increases, there are more molecules of substance in the same volume so they are packed closer together. collisions become more frequent so collisions with energy greater than the activation energy increases. therefore, rate of reaction increases.
what is the effect of temperature on the maxwell-boltzmann distribution
the curve shifts to right and lowers slightly. a greater proportion of molecules have energy greater than or equal to the activation energy. the area under the curve is the same
what is a catalyst and how does it work
a substance that increases the rate of reaction without being used up in the reaction. it provides an alternative reaction pathway with a lower activation energy for the reaction to occur
what is the effect of catalysts on the maxwell-boltzmann distribution
the shape of the maxwell-boltzmann curve doesn’t change but the position of the activation energy shifts to the left so more particles have sufficient energy to react.
how can rate of reaction be measured?
- time how long it takes for a reaction to complete
- measure loss of mass
- measure the amount of product formed
- colour change
- change in pH
two equations to work out rate of reaction
amount of product formed / time
amount of reactant used / time
define activation energy
the minimum amount of energy required for particles to react
why don’t most reactions take place at room temperature
only a small number of particles have energy greater than the activation energy and so only a small proportion of collisions will be successful
