Unit 8 'Rate of reaction' Grade 8 (IV/2)

The rate of a reaction increases as temperature__________________.

• Decreases

• Stays the Same

• Increases

A temperature increase causes the particles ......

• to slow down

• collide higher

• move faster

• in the right order

Products will form faster if____________

• the particle size of the reactants are larger.

• concentration of the reactants are increased.

• temperature is decreased.

• the reaction is not stirred.

A ______________ is a substance that increases the rate of a reaction without being used up during the reaction.

• catalyst

• reactant

• product

• solute

Smaller particle size allows for a _________ surface area to be exposed for the reaction.

• larger

• smaller

Increasing the concentration of the reactants will slow down the reaction.

• false

• true

Why does a higher concentration increase the rate of reaction?

• it increases the amount of reactants

• it increases the energy of particle collisions

• it lowers the activation energy

• it increases the frequency of particle collisions

How does a catalyst work in speeding up a reaction?

• By lowering the activation energy or reaction

• by making them more available

• by giving them more energy

The minimum amount of energy needed for colliding particles to react is called the

• Chemical Energy

• Activation Energy

• Kinetic Energy

• Potential Energy

A catalyst increases the efficiency of collisions between reactants.

• true

• false