Question -
Answer -
is thermodynamically feasible asis apparent from the Gibbs energy value. Why doesit not take place at room temperature?
Answer
The change in Gibbs energy isrelated to the equilibrium constant, K as
At room temperature, allreactants and products of the given reaction are in the solid state. As aresult, equilibrium does not exist between the reactants and the products.Hence, the reaction does not take place at room temperature. However, at ahigher temperature, chromium melts and the reaction takes place.
We alsoknow that according to the equation
Increasing the temperatureincreases the value of 
making the value of 
more and more negative.Therefore, the reaction becomes more and more feasible as the temperature isincreased.