Edexcel GCSE Chemistry Topic 7 Rates of reaction and energy changes overview quiz quiz

Any amount of energy at all, however small, when the particles meet

A catalyst particle attached to each of the colliding reactants

Exactly the same mass as one another before they collide

At least the activation energy and the correct orientation

There are more particles in the same volume, so collisions are more frequent

It lowers the activation energy that is needed for a successful collision to happen

It raises the overall temperature of the reacting solution

It removes the catalyst from the reaction mixture

Only because the particles collide a little more often than they did before heating

Particles collide more often and a greater proportion exceed the activation energy

It lowers the activation energy required for the reaction to take place

It increases the surface area of the solid reactant particles

Marble chips and acid with the gas collected in a gas syringe

Electrolysis of copper sulfate solution using inert electrodes

Sodium thiosulfate and hydrochloric acid forming a precipitate

Neutralisation of acid and alkali in an insulated polystyrene cup

$0.5$ cm$^3$/s

$20$ cm$^3$/s

$800$ cm$^3$/s

$2.0$ cm$^3$/s

By providing an alternative pathway with a lower activation energy

By raising the activation energy that the colliding particles must reach

By being rapidly used up and consumed during the reaction

By increasing the temperature of the surroundings

takes in energy from the surroundings so the temperature falls

transfers energy to the surroundings and the temperature rises

does not change the temperature of the surroundings at all

only ever happens when a catalyst is present

higher in energy than the reactants

at the same energy as the reactants

lower in energy than the reactants

at the top of the activation energy peak

Breaking chemical bonds always releases energy to the surroundings

Making new chemical bonds always takes in energy from the surroundings

Bond breaking and bond making involve no energy change at all

Breaking bonds is endothermic and making bonds is exothermic

$-150$ kJ/mol, exothermic

$+150$ kJ/mol, endothermic

$+1550$ kJ/mol, endothermic

$-1550$ kJ/mol, exothermic

It is completely destroyed during the reaction

It is not used up, so it can be reused

It dissolves completely into the mixture

It increases the temperature of the mixture

The temperature of the mixture is at its very highest right at the start of the reaction

A catalyst is only ever added to the mixture at the very start of the reaction

The reactant concentration is highest at the start, so collisions are most frequent

The products formed actively slow the reaction down right at the start