The Arrhenius Equation

Question 1

How does temperature affect the rate constant (k)?

Answer 1

• temperature increases
• rate of reaction increases
• rate constant increases

EXPONENTIAL INCREASE

Question 2

State and explain the Arrhenius Equation.

Answer 2

K = A e^ (Ea/RT)

K = rate constant
A = pre-exponential factor
e^ (Ea/RT) = exponential factor

Question 3

State and explainthe logarithmic form of the Arrhenius Equation.

Answer 3

lnk = -Ea / RT + lnA

lnk = y
-Ea / R = gradient (m)
1/T = x
lnA = y-intercept

Question 4

How can you calculate Ea ( activation energy)?

Answer 4

1. Find gradient of lnk / 1/T
2. Multiply by R ( 8.314) = Ea in J/mol
3. Check units and convert if required

Question 5

How can you calculate A?

Answer 5

1. Y-intercept = lnA
   2 e^lnA = A