Chemical Industry 4: Arrhenius Equation Flashcards
What does the Arrhenius Equation shoe the link between
Rate constant, k
Activation energy, Ea
Temperature, T
What is the Arrhenius Equation ( although given on data sheet )
k = Ae^ -Ea/ RT
What is the Arrhenius Equation in logarithm form ( although given on data sheet )
ln k = - Ea/RT + lna
k = ??? ( units )
Rate constant ( unit vary depending on order of reaction )
A = ??? ( units )
Arrhenius constant ( sane units as k )
Ea = ??? ( units )
Activation energy ( J mol^-1 )
- answer often wanted in KJ mol-1 = divide by 1000
R = ??? ( units )
Gas constant = 8.31 J mol^-1 K^-1 ( given on data sheet )
T = ??? ( units )
Temperature ( K )
= 0° = 273 K
What is another name for e^-Ea/RT part of Arrhenius Equation
Exponential factor
Definition of exponential factor
Proportion of molecules that have sufficient energy for a reaction to take place
What is another name “A”( Arrhenius constant ) part of Arrhenius Equation
Pre - exponential factor or frequency factor
Definition of pre- exponential factor or frequency factor
Accounts for the frequency of collisions with the correct orientation
What is special about the logarithmic form of the Arrhenius Equation
- plotting graph of ln k against 1/T gives a downward straight line graph in the form y = mx + c
What does each party of the logarithmic form of Arrhenius Equation equate to in the form y = mx +c
y = link
m = -Ea/ R
x = 1/T
c = ln A
What 2 parts of the Arrhenius Equation in logarithmic form can be found from plotting a graph of ln k against 1/T
- Ea, Activation energy ( gradient )
2. A, Arrhenius constant ( y intercept )
