Making Reactions go Faster 1

Question 1

using the logic of collision theory, what is a way that you could increase the rate of a reaction

Answer 1

• by increasing the frequency of collisions between reactant particles
• therefore increasing the frequency of successful collisions in order for the reaction to occur

Question 2

using the collision theory, what would you do with reactions in solutions in order to increase the rate of reaction

Answer 2

increase the concentration of the reactants

Question 3

why does an increase in the concentration of the reactants result in an increase in the rate of reaction

Answer 3

• there are more reactant particles per unit of volume
• meaning they are closer together and therefore the frequency of their collisions increases
• so the frequency of successful collisions also increases
• resulting in a higher rate of reaction

Question 4

line A and B are the same reaction. if you have a graph of volume of gas produced against time, with two lines (A having a steeper gradient than B and A leveling off before B but they both eventually level off at the same height), which line would indicate a quicker rate of reaction and why

Answer 4

• line A
• because a steeper gradient means that more gas was being produced in a given time than line B
• and the fact that line A leveled off first means that the reaction was complete before line B

Question 5

therefore which line would be showing the reaction that had the higher concentration of acid used

Answer 5

line A

Question 6

how do you increase the rate of reaction for gases without changing the volumes or temperatures of the gases (or adding a catalyst)

Answer 6

be increasing the pressure

Question 7

why does increasing the pressure lead to an increase in the rate of reaction

Answer 7

• similar to the reasons for concentration
• more reactant particles per unit of volume
• meaning more frequency collisions and therefore successful collisions
• leading to higher rate of reaction

Question 8

how do you increase the rate of reaction involving solids

Answer 8

by increasing the solids surface area

Question 9

why does an increase in the surface area of solids result in an increase int he rate of reaction

Answer 9

• an increase in surface area means that there is more of the solids surface for the other reactant to collide with
• meaning the frequency of collisions increases
• therefore the frequency of successful collisions increases leading to a higher rate

Question 10

does increasing the surface area of solid catalysts increase their effectiveness

Answer 10

yes