AQA GCSE Chemistry 4.6 The rate and extent of chemical change overview quiz quiz

How quickly reactants are used up or products are formed

The total mass of all the products formed

The final temperature reached by the reaction

The number of atoms present in the reactant particles only

By measuring the changing colour of the solution only

By recording the volume of gas collected over time

By weighing the empty gas syringe on a balance

By measuring only the final pH of the mixture

$0.5$ cm$^3$/s

$20$ cm$^3$/s

$2$ cm$^3$/s

$800$ cm$^3$/s

Read the matching value straight off the y-axis

Measure the total area underneath the curve

Find the final flat plateau value reached on the graph

Draw a tangent at that point and find its gradient

Particles must collide with at least the activation energy

Particles must always be heated to exactly room temperature

Particles must all be in the gas state before reacting

Particles must stop moving completely before they react

It gives each of the particles much more energy

More particles are exposed, so collisions are more frequent

It raises the temperature of the reaction mixture

It lowers the activation energy that the particles need to react

Only because the particles move faster, with no change to successful collisions

Only because there are more reacting particles present

Particles move faster and a greater proportion have the activation energy

Because the activation energy of the reaction falls

It is gradually used up and consumed during the reaction

It increases the overall energy change of the reaction

It raises the activation energy required, so it makes the whole reaction far slower overall

It provides an alternative pathway with a lower activation energy and is not used up

The forward and backward reactions occur at the same rate so amounts stay constant

The whole reaction has stopped completely and no further change can happen at all now

Only the forward reaction continues to happen now

All of the reactants have already been used up

The equilibrium shifts to support the change

The equilibrium shifts to oppose the change

The reaction stops

Nothing changes

The side that has more molecules of gas

It has no effect on the position

The side with fewer molecules of gas

Always towards the reactant side

Also exothermic

Neither, it has no energy change

Exothermic but smaller

Endothermic by the same amount