Higher Combined Science - Chemistry
paper 2(AQA GCSE 9-1) Pro Test
Questions With Solved Solutions.
what is a rate of reaction? - Answer the speed of a reaction
what is the equation for rate of reaction? - Answer quantity of reactant used up/time taken
or
quantity of product formed/time taken
what unit do we normally use for time? - Answer seconds
what unit do we normally use for mass? - Answer grams
what unit do we normally use for a rate of a reaction? - Answer grams/second
you can also measure a rate of a reaction using ... - Answer a graph
how do you calculate the gradient? - Answer change in y/change in x
what key factors affect the rate of reaction? - Answer temperature
pressure
concentration
surface area
catalysts
what happens to the rate as you increase the temperature? - Answer the rate increases
, what is concentration a measurement of? - Answer the number of particles dissolved in a given volume
of solvent
what is pressure a measurement of? - Answer the number of particles in a given volume of gas
what happens to the rate of a reaction when you increase its pressure or concentration? - Answer it
increases
what happens to a rate of reaction when you increase its surface area? - Answer it increases
what is a catalyst? - Answer a substance that speeds up a chemical reaction without being used up
how do a catalyst work? - Answer it decreases the activation energy that a reaction needs
what is the collision theory? - Answer chemical reactions can only take place if reaction particles collide
into each other with sufficient energy
what happens when the concentration, pressure or surface area is increased? - Answer the frequency
of collisions increases so the rate of reaction also increases
what happens when the temperature is increased? - Answer the frequency of collisions increases and
are made more energetic so the rate of reaction increases
what is a reversible reaction? - Answer where the products of a reaction can react again and produce
the original reactants
what is equilibrium? - Answer when the forward and reverse reactions happen at exactly the same rate
what is the le chateliers principle? - Answer if a system is at equilibrium and a change is made to the
conditions the system responds to counteract the change
paper 2(AQA GCSE 9-1) Pro Test
Questions With Solved Solutions.
what is a rate of reaction? - Answer the speed of a reaction
what is the equation for rate of reaction? - Answer quantity of reactant used up/time taken
or
quantity of product formed/time taken
what unit do we normally use for time? - Answer seconds
what unit do we normally use for mass? - Answer grams
what unit do we normally use for a rate of a reaction? - Answer grams/second
you can also measure a rate of a reaction using ... - Answer a graph
how do you calculate the gradient? - Answer change in y/change in x
what key factors affect the rate of reaction? - Answer temperature
pressure
concentration
surface area
catalysts
what happens to the rate as you increase the temperature? - Answer the rate increases
, what is concentration a measurement of? - Answer the number of particles dissolved in a given volume
of solvent
what is pressure a measurement of? - Answer the number of particles in a given volume of gas
what happens to the rate of a reaction when you increase its pressure or concentration? - Answer it
increases
what happens to a rate of reaction when you increase its surface area? - Answer it increases
what is a catalyst? - Answer a substance that speeds up a chemical reaction without being used up
how do a catalyst work? - Answer it decreases the activation energy that a reaction needs
what is the collision theory? - Answer chemical reactions can only take place if reaction particles collide
into each other with sufficient energy
what happens when the concentration, pressure or surface area is increased? - Answer the frequency
of collisions increases so the rate of reaction also increases
what happens when the temperature is increased? - Answer the frequency of collisions increases and
are made more energetic so the rate of reaction increases
what is a reversible reaction? - Answer where the products of a reaction can react again and produce
the original reactants
what is equilibrium? - Answer when the forward and reverse reactions happen at exactly the same rate
what is the le chateliers principle? - Answer if a system is at equilibrium and a change is made to the
conditions the system responds to counteract the change
