Temperature and Arrhenius equation

What does arrhenius equation do

Determines the effect of a temperature on the rate constant and consequently the ROR as temp direct prop- rate direct prop- k

State and explain the equation

k = A e-Ea/RT

A-Pre-exponential factor (takes into account the frequency of collisions with correct  orientation). This is essentially a constant

e-Ea/RT- Exponential factor (represents the proportion of molecules that exceed Ea)​

T = temperature in K​

R = gas constant​

Factors affecting k

• As temperature increases, collisions increase  (as particles are moving more quickly)​

• More particles are above Ea and so more collisions are successful​

• The increased frequency of collisions has a comparatively small effect compared with the increase in the number of particles with >Ea

Relationship between temp, rate and k

• As temperature increases, k increases​

• Roughly, for every 10°C increase the rate doubles and k doubles​

• This is an exponential relationship

How do you calculate Ea

1. Plot lnk against 1/t, giving downward straight line which gives:

   Gradient of -Ea/R

   Intercept of lnA on x axis

2. Now calculate Ea with equation