AQA GCSE COMBINED SCIENCE TRILOGY
HIGHER TIER PHYSICS PAPER 1H ACTUAL
2
⩥ slow reactions. Answer: rusting of iron
chemical weathering
⩥ fast reactions. Answer: burning
explosions
⩥ rate of reaction graphs. Answer: steeper line = faster rate
flat = reaction finished
higher line = more reactants and products
⩥ collision theory in rate of reaction. Answer: 1. collision frequency of
reacting particles
more collisions = faster rate
2. energy transferred during a collision
particles need to collide with enough energy to be successful
,⩥ factors affecting rate of reaction. Answer: 1. temperature
particles have more energy, collide more frequently
2. concentration or pressure
more particles in an area = more frequent collisions
3. surface area
smaller pieces = more area for collisions to happen on
⩥ catalyst. Answer: a substance that speeds up the rate of reaction
without being used up itself
⩥ catalyst's affect on rate of reaction. Answer: speed it up by decreasing
activation energy
do this by creating an alternative reaction pathway with lower activation
energy
e.g. enzyme
⩥ rate of reaction equation. Answer: amount of reactant used up or
amount of product formed / time
, ⩥ precipitate. Answer: a solid formed in a reaction
⩥ precipitate and colour change showing rate of reaction. Answer: can
observe how long it takes for a solution to lose or gain colour
can observe how long it takes a solution to become cloudy
⩥ change in mass showing rate of reaction. Answer: 1. put reaction on
scale
2. is a gas is produced, the mass will decrease
3. the quicker it decreases, the faster the reaction
⩥ volume of gas showing rate of reaction. Answer: gas syringe to
measure vol of gas being produced
more gas given off in one time interval = faster rate
⩥ finding reaction rates from graphs. Answer: 1. calculating mean rate
overall change in y axis / total time taken
2. calculating rate at a point
draw a tangent at the point and find the gradient
⩥ reversible reaction. Answer: a + b ↔ c + d
HIGHER TIER PHYSICS PAPER 1H ACTUAL
2
⩥ slow reactions. Answer: rusting of iron
chemical weathering
⩥ fast reactions. Answer: burning
explosions
⩥ rate of reaction graphs. Answer: steeper line = faster rate
flat = reaction finished
higher line = more reactants and products
⩥ collision theory in rate of reaction. Answer: 1. collision frequency of
reacting particles
more collisions = faster rate
2. energy transferred during a collision
particles need to collide with enough energy to be successful
,⩥ factors affecting rate of reaction. Answer: 1. temperature
particles have more energy, collide more frequently
2. concentration or pressure
more particles in an area = more frequent collisions
3. surface area
smaller pieces = more area for collisions to happen on
⩥ catalyst. Answer: a substance that speeds up the rate of reaction
without being used up itself
⩥ catalyst's affect on rate of reaction. Answer: speed it up by decreasing
activation energy
do this by creating an alternative reaction pathway with lower activation
energy
e.g. enzyme
⩥ rate of reaction equation. Answer: amount of reactant used up or
amount of product formed / time
, ⩥ precipitate. Answer: a solid formed in a reaction
⩥ precipitate and colour change showing rate of reaction. Answer: can
observe how long it takes for a solution to lose or gain colour
can observe how long it takes a solution to become cloudy
⩥ change in mass showing rate of reaction. Answer: 1. put reaction on
scale
2. is a gas is produced, the mass will decrease
3. the quicker it decreases, the faster the reaction
⩥ volume of gas showing rate of reaction. Answer: gas syringe to
measure vol of gas being produced
more gas given off in one time interval = faster rate
⩥ finding reaction rates from graphs. Answer: 1. calculating mean rate
overall change in y axis / total time taken
2. calculating rate at a point
draw a tangent at the point and find the gradient
⩥ reversible reaction. Answer: a + b ↔ c + d
