Effect of Temperature on the Rate Constants

Question 1

what happens to the rate and the rate constant when temperature increases?

Answer 1

• the rate increases
• the rate constant also increases

Question 2

what factors contribute to the increase in rate and rate constant when the temperature increases?

Answer 2

• increasing temperature shifts the Boltzmann distribution to the right, increasing the number of molecules that have energy greater than or equal to activation energy
• as temperature increases, particles move faster and collide more frequently with the correct orientation and sufficient energy

Question 3

how can we link the equation of a line to arrenhius’ equation?

Answer 3

lnK = - Ea/R x 1/T + lnA
y =mx+c

Question 4

how do we find Ea?

Answer 4

Ea= - (gradient x 8.314)

Question 5

what graph do we plot for arrenhius’ equation?

Answer 5

lnK = y axis
1/T = x axis

Question 6

what is the y-intercept?

Answer 6

• lnA

Question 7

how could a student determine the activation energy for a reaction graphically?

Answer 7

• plot a graph using lnK and 1/T
• measure the gradient by doing change in y over change in x
• Ea = - (gradient x 8.314)

Question 8

how do we find the pre-exponential factor, A?

Answer 8

• A = e to the power of the y intercept