Spontaneity at Different Temperatures
Most
commonly, we are given standard
free energy (ΔGº)
for a reaction, which is at 1 atm and 25ºC (and 1 M if it's a
solution). But theoretically, we can drive ANY reaction forward if
we supply it with enough energy (heat) ... as long as we overcome the
activation energy barrier.
To calculate the free energy change of a reaction at any temperature, we use the formula:
To calculate the free energy change of a reaction at any temperature, we use the formula:
where
Q is the reaction quotient. It is created the exact same way as the
equilibrium constant, K, except the current
concentrations are used instead of the equilibrium concentrations.
It is also worth noting that we can calculate the equilibrium constant (K) from the standard free energy, and vice versa:
It is also worth noting that we can calculate the equilibrium constant (K) from the standard free energy, and vice versa:
