Rates and Equillibrium Flashcards
explain how increasing the SA increases the rate of reaction
- increases the number of particles available for reaction
- this increases the frequency of collisions
- meaning more collisions in a given period of time have the required activation energy
- this increases the rate of reaction
what are the 3 ways to measure a rate of reaction
- measure the rate at which a reactant is used up over time
- measure the rate at which a product is formed up over time
- measure the decreasing light passing through a solution
what is the equation to measure the rate at which a reactant is used up over time
rate of reaction = quantity of reaction used / time
what is the equation to measure the rate at which a product is formed over time
rate of reaction = quantity of product formed / time
what does collisions mean
chance of reaction
what does activation energy mean
the minimum amount of energy required for a reaction to take place
why does raising the temperature increase the rate of reaction
collisions theory tells us:
- particles collide more often
- particles collide with more energy
why does particles colliding more often and with more energy increase the rate of reaction
more often: more chances for them to react
more energy: particles moving around more quick]kly have more energy - any collisions they have will be more energetic
what is a catalyst
substances that speed up chemical reactions without being used up in the reaction
what does a catalyst do and how
increases the rate of reaction
by providing an alternative pathway
do catalysts produce more product
no, always the same amount of product just more quickly
how much catalyst is needed to increase the rate of reaction
only a very small amount
describe the practical decomposition of hydrogen peroxide experiment
- measure 10cm cubed of hydrogen peroxide solution into conical flask
- add the potential catalyst (measure with a spatula) to the hydrogen peroxide solution
- reassemble apparatus quickly (and start stopwatch) to avoid losing any gas
- note time taken for 20cm cubed of gas to be collected
- repeat steps with each potential catalyst
independent variable of the practical decomposition of hydrogen peroxide experiment
catalyst
dependent variable of the practical decomposition of hydrogen peroxide experiment
the reaction
control variable of the practical decomposition of hydrogen peroxide experiment
the 10 cm cubed of hydrogen peroxide solution
what is an irreversible reaction
A + B -> C + D
has one arrow pointing to the products
what is a reversible reaction
A + B C + D
products C + D can react with each other to reform reactants A + B
is a reversible reaction endothermic or exothermic
in any reversible reaction, one reaction will be exothermic and the other will be endothermic
what is a salt
when an acid is neutralised with a base
what is water of crystallisation
water molecules in the latice structure
write a word equation to show the equilibrium between hydrated and anhydrous copper sulfate crystals
And how to reverse it
hydrous copper sulfate (heat, endothermic, putting energy in) –> anhydrous copper sulfate + water
REVERSE REACTION:
add water back to anhydrous copper sulfate
energy released and reaction gets hot, exothermic
what colour is hydrous copper sulfate
blue
what colour is anhydrous copper sulfate
white
what could anhydrous copper sulfate crystals be used to test for
water
how can we change the direction of reversible reactions
by changing the conditions
what is meant by equilibrium
when the forward and reverse reactions take place at exactly the same rate
