[sci0x]

If activation enthalpy for a first order reaction is 76.7 kJ mol-1. How many times faster will the reaction occur at 50 degrees Celsius than 0 degrees Celsius?

[Borek]

Arrhenius equation.

Unless I am wrong - it happens!

[sci0x]

You mean this equeation  k=A*exp(-Ea/R*T) ?
How does this help?

[Borek]

What is k? What is Ea? WHat is goven? What do you have to find?

[plu]

In this case, you might want to use version 2.0 of the arrhenius equation  

ln (k₂/k₁) = (E_A/R)(1/T₁ - 1/T₂)

You will want to find the ratio k₂/k₁.

[Borek]

In this case, you might want to use version 2.0 of the arrhenius equation  

ln (k₂/k₁) = (E_A/R)(1/T₁ - 1/T₂)

You will want to find the ratio k₂/k₁.

More confusing then helpfull.

As you have alredy solved the question, at least show sci0x that it is the same equation.

[plu]

More confusing then helpfull.

As you have alredy solved the question, at least show sci0x that it is the same equation.

Apologies.  I assumed he had covered both equations in class already.  To get the second form of the equation, you first take the ln of both sides.

(1)  ln k₁ = ln A + (-E_a1/R)(1/T)
(2)  ln k₂ = ln A + (-E_a2/R)(1/T)

Now, noting that A is equal in both equations, substracting (2) from (1) gives the second form of the Arrhenius equation