rates of reaction 4.1 Flashcards
what is the amount of energy particles require to react called
activation energy
what does the rate of a reaction depend on
collision frequency
percentage success
factors affecting collision frequency
solution concentration
solid surface area
factors affecting percentage success
temperature
catalysts
why does an increase in surface area increase rate
more of the solid is exposed, increasing collision frequency, more successful collisions per unit time
why does an increase in concentration/pressure increase rate
there are more particles per unit volume, collision frequency is higher so there are more successful collisions per unit time
what experiment demonstrates the effect of surface area
marble chip experiment
what experiment demonstrates the effect of pressure/concentration
disappearing cross experiment
what is the relationship between rate and concentration
proportional
why does an increase in temperature increase the rate
the particles have more kinetic energy, the percentage of collisions with enough energy is higher, there are more successful collisions per unit time
what experiment is used to demonstrate the effect of temp on rate
reacting magnesium with hydrochloric acid
what are catalysts
substances which increase rate of reaction, whilst remaining chemically unchanged
how do catalysts increase the rate of reaction
they provide an alternative route with a lower activation energy, therefore the percentage of collisions with enough energy is higher, so there are more successful collisions per unit time
what experiment demonstrates the effect of catalysts on rate
hydrogen peroxide experiment
