rates of reaction Flashcards
what are the four ways that we can increase the rate of a reaction?
surface area
temperature
concentration
presence of a catalyst
what is a variable?
a factor that can affect the results of an experiment
what is an independent variable?
the part of your experiment that you change. Y AXIS
what is a dependent variable?
the part of your experiment you are measuring. X AXIS
what is a control variable?
the things you have changed in an experiment but you need to keep the same
what is the collision theory?
particles must collide in order to react with eachother
what is the experiment to test the effect of surface area?
marble chips and hydrochloric acid.
CaCO3
calcium carbonate + hydrochloric acid = calcium chloride + water
how do we know when a reaction is finished?
the line levels out and becomes horizontal
what is the experiment to test the effect of concentration?
hydrochloric acid + magnesium = magnesium chloride + hydrogen
2HCl + Mg = MgCl + H2
what is the experiment to test the effect of temperature?
heated up sodium thiosulphate and hydrochloric acid to see if the pencil cross disappeared
what is the word equation for our test on the effect of temperature?
sodium thiosulphate + hydrochloric acid = (arrow) sodium chloride + water + sulphur dioxide + sulphur
what is the experiment to test the effect of catalysts?
hydrogen peroxide (arrow) water + oxygen
2H(2)O(2) (Arrow) 2H(2)O + O(2)
what is the activation energy?
the minimum amount of energy needed to start a reaction. if the activation energy is not met, there will be no reaction
how can we visually see how fast a rate of reaction occurs from the products produced?
colour change
gas formation
what is the effect of concentration on the rate of reaction?
when you have a HIGHER CONCENTRATION there are more articles which means MORE COLLISIONS
what is the effect of temperature on the rate of reaction?
when particles are heated they gain KINETIC ENERGY. this means that particles will collide more often and also they have more energy and so the activation energy is achieved more frequently
what is the effect of catalysts on the rate of reaction?
when a catalyst is involved in a reaction, they dont change neither itself or the products. catalysts lower the activation energy by offering an alternative route for the reaction
what is the effect of surface area on the rate of reaction?
the smaller the chips the larger the surface area. this allows more collisions at the surface which results in the increase in the rate of reaction
