factors affecting the rate of reaction. Flashcards
how does surface area affect the rate of reaction?
large pieces of solid have small SA.
small pieces of solid eg: powder have large SA.
increase SA of solid reactants, increases ROR.
larger SA more of the solid is exposed to other reactants.- more successful, frequent collisions between particles.
how does temperature affect rate of reaction?
increase temp increases ROR.
particles have more Ke. higher proportion of particles have energy that is or exceeds the activation energy.
more frequent , successful collisions.
how does concentration/ pressure affect the rate of reaction?
increase the concentration of solutions or pressure with gases increases ROR.
more particles in a given volume.
more frequent, successful collisions.
how do catalysts affect the rate of reaction?
don’t increase frequency of collisions.
using one increases ROR, providing particles with an alternative reaction pathway with a lower activation energy.
more successful collisions as more particles have up to or more than the required activation energy.
they aren’t used up during a reaction.
how can you find out the rate of reaction?
monitoring the amount of reactants over time or monitoring the amount of products made over time.
what does the gradient of the line tell us?
rate of reaction at that time.
if the line has a steeper gradient what does that suggest?
faster the reaction.
how do you calculate the rate of reaction at a specific time?
draw a tangent to the curve then calculate it’s gradient.
what’s the formula for the mean rate of reaction?
quantity of reactant used/time.
or
quantity of product formed/time.
what are the terms on when a particle can react?
must collide with a certain minimum amount of energy.
what is the minimum amount of energy that particles must have in order to react?
activation energy.
when does the rate of a chemical reaction increase?
what does this do?
surface area to volume ratio of any solid reactants is increased.
increases the frequency of collisions between reacting particles.
true of false: particles collide all of the time.
how many lead to reactions?
true.
only a few.
what things can increase surface area?
more particles in a given volume.
particles closer together.
more frequent, successful collisions.
increases reaction rate.
what are the disadvantages of catalysts?
disadvantages:
expensive to buy/ make.
many are precious metals.
can become poised
