Write the formula for determining the change in Gibbs free e

Write the formula for determining the change in Gibbs free energy or delta G of a reaction. Describe how you would determine the values for the two key variables K_eq and Q. Calculate the delta G for a reaction with three different sets of K_eq and Q values of your choice. Submit your results through Canvas.

Solution

1). The formula to calculate the change in Gibb\'s free energy G of a reaction is,

G (Gibb’s energy) = H (change in energy) - T S (change in entropy at constant temperature T).

Means, the value of Gibb’s free energy is dependent on the entropy of the system and the change in energy. But, the delta S value may be positive or negative independent of the delta H value, both may be positive, both may be negative or one can be positive and another negative, vice versa.

In an endergonic reaction, the delta G value is positive and the delta G is negative. The entropy is positive for exergonic reactions (spontaneous reactions). Whereas the endergonic reactions take energy from the surroundings.

a). If the delta H is positive and delta S is negative, the reaction is not thermodynamically favoured.

b). If the delta H is negative and delta S is positive, the reaction is thermodynamically favoured.

c). If both the delta H and delta S are either positive or negative, the reaction favourability depends upon the temperature.