Self assessment
Question 1 of 4
Which of the following is the best explanation of why the rate increases when temperature increases?
A
Particles move faster
B
There are more collisions
C
The average kinetic energy of the particles increases so more particles have sufficiently high energy to successfully collide.
The rate of a reaction can be altered by changing the concentration of the reactants. Which is the best explanation of how concentration affects rate?
A
The higher the concentration the higher the average energy of the reactant.
B
The higher the concentration the more reactant particles there are
C
By increasing the concentration of either reactant we are increasing the number of particles which have sufficient energy to react.
D
Increasing the concentration increases the frequency of collisions. Although the proportion of particles with sufficient energy is the same the actual number is increased so more successful collisions.
A reaction is carried out between two invisible gases in a sealed container (the volume of which can be altered by moving a plunger) and the reaction produces a new brown gas. Which of the following would lead to an increase in the rate of formation of the brown gas assuming that the quantity of the two reacting gases is the same in each case?
A
Cool the container
B
Move the plunger to increase the volume of the container
C
Expose the container to UV
D
Push the plunger in so that the volume of the reaction vessel is halved.
2g of copper oxide is reacted with 20cm3 sulfuric acid in a concial flask to make copper (II) sulfate. From the list below select the conditions which you think will lead to the highest rate of reaction.
A
Powdered copper oxide, 2 mol dm-3 H2SO4 and a temperature of 10 °C
B
Powdered copper oxide, 0.02 mol dm-3 H2SO4 and a temperature of 50 °C
C
Powdered copper oxide, 2 mol dm-3 H2SO4 and a temperature of 70 °C
D
A lump of copper oxide, 2 mol dm-3 H2SO4 and a temperature of 50 °C