AQA GCSE CHEMISTRY PAPER 1
AND 2 ACTUAL EXAM LATEST
UPDATE
What is a compound? - ANSWER --A substance made up of two or more elements
chemically combined in fixed proportions
How are the elements in a compound separated? - ANSWER --By chemical reaction
What is an atom? - ANSWER --Smallest part of an element that can exist
What is an element? - ANSWER --A substance made up of one type of atom
How are elements represented? - ANSWER --Using symbols, in the periodic table
Approximately how many elements are there? - ANSWER --100
How are chemical reactions represented? - ANSWER --By word or symbol equations
Which group of the periodic table includes sodium and potassium? - ANSWER --Group 1,
alkali metals
,How do you measure the rate of a reaction? - ANSWER --By measuring the quantity of a
reactant used or the quantity of product formed over time
What is the equation for calculating the mean rate of a reaction by measuring the amount of
reactant used? - ANSWER --Mean rate of reaction = quantity of reactant used/time taken
What is the equation for calculating the mean rate of a reaction by measuring the amount of
product formed? - ANSWER --Mean rate of reaction = quantity of product formed/time
taken
What units can you measure the rate of a reaction in? - ANSWER --g/s or cm3/s or mol/s
How do you calculate the rate of a reaction at a specific time from graph of the quantity of
reactant used or the quantity of product formed? - ANSWER --By measuring the gradient
of a tangent drawn at that specific time on the graph
What are the five factors that can affect the rate of a reaction? - ANSWER --Concentration
of reactants in solution, pressure of reacting gases, surface area of solid reactants, temperature
and the presence of a catalyst
According to collision theory why does increasing temperature increase the rate of the
reaction? - ANSWER --It increases the frequency of collisions and makes the collision
more energetic and so increases the rate of reaction
How do you increase the surface area of a solid reactant? - ANSWER --Grind it into a
powder that has smaller particle size
,What effect does increasing the temperature of a reaction by 10°C have on the rate of a
reaction? - ANSWER --It doubles it
What is a catalyst? - ANSWER --A chemical that changes the rate of a chemical reaction
but is not used up in the reaction
How do catalysts increase the rate of a reaction? - ANSWER --By providing a different
pathway for the reaction that has a lower activation energy
How do you know in a reaction that a chemical is used in a reaction is a catalyst? -
ANSWER --It is not included in the chemical equation for the reaction
What theory can we use to explain how various factors affect the rate of a reaction? -
ANSWER --Collision theory
What is collision theory? - ANSWER --Chemical reactions can occur only when reacting
particles collide with each other and with sufficient energy
What is the activation energy of a reaction? - ANSWER --The minimum amount of energy
that particles must have to react
According to collision theory why does increasing concentration of reactant in solution increase
the rate of the reaction? - ANSWER --It increases the frequency of collisions and so
increases the rate of reaction
According to collision theory why does increasing the pressure of reacting gases increase the
rate of the reaction? - ANSWER --It increases the frequency of collisions and so increases
the rate of reaction
, According to collision theory why does increasing the surface area of solid reactants in solution
increase the rate of the reaction? - ANSWER --It increases the frequency of collisions and
so increases the rate of reaction
What is a reversible reaction? - ANSWER --Where the products of a chemical reaction can
react to produce the original reactants
What is the symbol used in reversible reaction equations that shows that the reaction is
reversible? - ANSWER --
How can you change the direction of a reversible reaction? - ANSWER --By changing the
conditions; for example heating or cooling the reaction
Describe the energy changes in a reversible reaction - ANSWER --One direction will be
exothermic and the other direction endothermic
When is equilibrium in a reversible reaction achieved in apparatus which prevents the escape of
reactants and products? - ANSWER --When the rate of the forward and reverse reactions
occur at exactly the same rate
What affects the relative amount of all the reactants and products at equilibrium in a reversible
reaction? - ANSWER --The conditions
What happens to an equilibrium if any of the conditions change? - ANSWER --The system
responds to counteract the change
What does Le Chatelier's principle predict? - ANSWER --The effects of changing conditions
on a system at equilibrium
AND 2 ACTUAL EXAM LATEST
UPDATE
What is a compound? - ANSWER --A substance made up of two or more elements
chemically combined in fixed proportions
How are the elements in a compound separated? - ANSWER --By chemical reaction
What is an atom? - ANSWER --Smallest part of an element that can exist
What is an element? - ANSWER --A substance made up of one type of atom
How are elements represented? - ANSWER --Using symbols, in the periodic table
Approximately how many elements are there? - ANSWER --100
How are chemical reactions represented? - ANSWER --By word or symbol equations
Which group of the periodic table includes sodium and potassium? - ANSWER --Group 1,
alkali metals
,How do you measure the rate of a reaction? - ANSWER --By measuring the quantity of a
reactant used or the quantity of product formed over time
What is the equation for calculating the mean rate of a reaction by measuring the amount of
reactant used? - ANSWER --Mean rate of reaction = quantity of reactant used/time taken
What is the equation for calculating the mean rate of a reaction by measuring the amount of
product formed? - ANSWER --Mean rate of reaction = quantity of product formed/time
taken
What units can you measure the rate of a reaction in? - ANSWER --g/s or cm3/s or mol/s
How do you calculate the rate of a reaction at a specific time from graph of the quantity of
reactant used or the quantity of product formed? - ANSWER --By measuring the gradient
of a tangent drawn at that specific time on the graph
What are the five factors that can affect the rate of a reaction? - ANSWER --Concentration
of reactants in solution, pressure of reacting gases, surface area of solid reactants, temperature
and the presence of a catalyst
According to collision theory why does increasing temperature increase the rate of the
reaction? - ANSWER --It increases the frequency of collisions and makes the collision
more energetic and so increases the rate of reaction
How do you increase the surface area of a solid reactant? - ANSWER --Grind it into a
powder that has smaller particle size
,What effect does increasing the temperature of a reaction by 10°C have on the rate of a
reaction? - ANSWER --It doubles it
What is a catalyst? - ANSWER --A chemical that changes the rate of a chemical reaction
but is not used up in the reaction
How do catalysts increase the rate of a reaction? - ANSWER --By providing a different
pathway for the reaction that has a lower activation energy
How do you know in a reaction that a chemical is used in a reaction is a catalyst? -
ANSWER --It is not included in the chemical equation for the reaction
What theory can we use to explain how various factors affect the rate of a reaction? -
ANSWER --Collision theory
What is collision theory? - ANSWER --Chemical reactions can occur only when reacting
particles collide with each other and with sufficient energy
What is the activation energy of a reaction? - ANSWER --The minimum amount of energy
that particles must have to react
According to collision theory why does increasing concentration of reactant in solution increase
the rate of the reaction? - ANSWER --It increases the frequency of collisions and so
increases the rate of reaction
According to collision theory why does increasing the pressure of reacting gases increase the
rate of the reaction? - ANSWER --It increases the frequency of collisions and so increases
the rate of reaction
, According to collision theory why does increasing the surface area of solid reactants in solution
increase the rate of the reaction? - ANSWER --It increases the frequency of collisions and
so increases the rate of reaction
What is a reversible reaction? - ANSWER --Where the products of a chemical reaction can
react to produce the original reactants
What is the symbol used in reversible reaction equations that shows that the reaction is
reversible? - ANSWER --
How can you change the direction of a reversible reaction? - ANSWER --By changing the
conditions; for example heating or cooling the reaction
Describe the energy changes in a reversible reaction - ANSWER --One direction will be
exothermic and the other direction endothermic
When is equilibrium in a reversible reaction achieved in apparatus which prevents the escape of
reactants and products? - ANSWER --When the rate of the forward and reverse reactions
occur at exactly the same rate
What affects the relative amount of all the reactants and products at equilibrium in a reversible
reaction? - ANSWER --The conditions
What happens to an equilibrium if any of the conditions change? - ANSWER --The system
responds to counteract the change
What does Le Chatelier's principle predict? - ANSWER --The effects of changing conditions
on a system at equilibrium
