rates of reaction Flashcards
what is the rate of a chemical reaction?
how fast the reactants are changed into products.
what is one of the slowest rates of reaction?
rusting of iron.
what is an example of a moderate speed reaction?
magnesium metal reacting with acid to produce a gentle stream of bubbles.
give an example of a fast reaction.
burning.
how can you find the speed of a reaction?
by recording the amount of product formed.
what shows how fast the rate of reaction is on a graph?
the steepness of the line.
how do you know a reactant is being used up on a graph?
the line becomes less steep.
what must particles do in order to react?
collide with enough energy.
what is the collision theory?
the things that the rate of a chemical reaction depends on.
name 2 things that the rate of a chemical reaction depends on.
the collisions frequency and the energy transferred during a collision.
what do more collisions do?
make the reaction faster.
why do particles need enough energy?
to ensure a successful collision happens.
what is activation energy?
the minimum amount of energy that particles need need to react.
why is activation energy important in rates of reaction?
to make sure that the bonds are broken so that a reaction can start.
what four things do rate of reaction depend on?
temperature
concentration of a solution or the pressure of gas
surface area
the presence of a catalyst.
what do more collisions do?
increase the rate of reaction.
what happened when the temperature is increased?
the particles move faster.
what happens when the particles are moving faster?
they will collide more frequently.
what happens when a solution is made more concentrated?
there are more particles in the same volume of solvent.
what happens when the pressure of gas is increased?
the same number of particles occupy a smaller space.
what do more particles in a smaller space do?
make collisions between particles more frequent.
what does breaking a solid reactant into smaller pieces do?
increase the surface area to volume ratio.
what is a catalyst?
a substance that speeds up a reaction without being used up in the reaction itself.
how do catalysts work?
they decrease the activation energy in a reaction.
how do catalysts decrease the activation energy in a reaction?
by providing an alternative reaction pathway with a lower activation energy.
what is reproducibility?
when something can be repeated by another person and still getting a different result x
what do you react together in the disappearing cross practical?
sodium thiosulfate and hydrochloric acid
