Kinetics

Question 1

What are the 5 factors that increase the rate of reaction?

Answer 1

-increase temperature
-increase concentration
-use smaller pieces of solid
-add a catalyst
-increase pressure for reactants with gas reactants

Question 2

How does increasing temperature increase rate of reaction?

Answer 2

as temperature increases, more particles have energy above the activation energy, so more high energy collisions per second

Question 3

How does increasing concentration increase rate of reaction?

Answer 3

as there are more particles per unit volume, there is a higher collision frequency and so more successful collisions per second

Question 4

How does using smaller pieces of solid increase rate of reaction?

Answer 4

smaller pieces mean a larger surface area, meaning more successful collisions per second

Question 5

How does using a catalyst increase rate of reaction?

Answer 5

a catalyst increases the rate of reaction by providing an alternate reaction pathway of lower activation energy, without being used up

Question 6

Why does increasing temperature have a greater effect on rate than increasing concentration?

Answer 6

because temperature effects rate exponentially whereas concentration effects rate in a linear fashion. increasing temperature means many more particles have energy above the activation energy, whereas whatever you increase concentration will have the exact same effect on the frequency of successful collisions

Question 7

What are the two calorimetry equations?

Answer 7

q=mcΔT
ΔH=-q/moles

Question 8

What is m, in mcΔT?

Answer 8

the mass of what is getting hotter, usually the water

Question 9

What do you have to remember when using the q value in q/moles?

Answer 9

before using the number from q=mcΔT, divide by 1000 to put it into KJ

Question 10

What is the most common reason for the student calculated value being lower than the true value of ΔH?

Answer 10

heat energy is lost to the surroundings