What name is given to the minimum amount of energy needed by particles for them to react when they collide?
Activation energy
Catalytic energy
Threshold energy
Which of the following would speed up a reaction?
Using lumps instead of powder
Increasing the concentration of an acid
Decreasing the temperature
Which of the following will increase the frequency of successful collisions?
Increasing the temperature
Decreasing the pressure
Decreasing the concentration
Which of the following statements about catalysts is false?
They speed up reactions
They provide an alternative reaction pathway with a lower activation energy
They become chemically changed at the end of the reaction
Which of the following will increase the proportion of successful collisions?
Increasing the pressure
Increasing the concentration
Which of the following would give a steeper curve on a graph of volume of gas against time?
Low temperature
Low concentration
Using a catalyst
If reaction A was repeated, using the same quantities of reactants but at a lower temperature, how would you describe the shape of the graph?
The graph will be steeper, and finish at the same volume produced (60 cm3) at a quicker time
The graph will be less steep and finish at 30 cm3
The graph will be less steep, and finish at the same volume produced (60 cm3), but at a later time
Using the particle theory, which of the following correctly explains why a higher temperature increases the rate of reaction?
As temperature increases, particles gain more energy resulting in a greater chance of a successful collision
As temperature increases, particles gain more energy and more collisions occur
As temperature increases, particles lose energy resulting in fewer successful collisions
At what time did reaction A finish?
20 seconds
30 seconds
50 seconds
2.5 g of a catalyst was added to speed up a chemical reaction. How much catalyst was there at the end of the reaction?
Less than 2.5 g
More than 2.5 g
Exactly 2.5 g