[Chaste]

as above.

[Schrödinger]

I don't think so, or atleast it doesn't change appreciably (very very negligible). If it were to vary with temperature, we wouldn't be able to measure rate constant at different temperatures.

I think A basically depends on the type of reaction that goes on

[gertrudetrumpet]

from my knowledge, the A factor in arrhenius' equation is the steric factor and part of the collision frequency, which is equal to (sigma)vn^2, where sigma is collision cross section, v is relative velocity, and n is avogadro's number. I am not sure, but wouldn't temperature increase mean more kinetic energy and more motion, thus a larger relative velocity and larger A value? I am not sure if this will be noticeable in calculations but I do think it will increase.

[juanrga]

as above.

A is the frecuency factor only for first order kinetics, when A has units of s^-1.

The Arrhenius equation

$$ k=A\exp \left(-\frac{E_a}{RT} \right) /$$

is an approximation to generalized equations as

$$ k = A \left( \frac{T}{T_0} \right) \exp \left( -\frac{E_a}{RT} \right) /$$

or

$$ k = A \exp \left( - \left( \frac{E_a}{RT} \right)^\beta \right) /$$