Enter the temperature (K) and the equilibrium constant into the calculator to determine the Standard Free Energy.

## Standard Free Energy Formula

The following equation is used to calculate the Standard Free Energy.

**SFE = -R*T*ln(K)**

Variables:

- Where SFE is the Standard Free Energy (Joules)
- T is the temperature (K)
- K is the equilibrium constant
- R is the universal gas constant (8.3145 J/mol-K)

## How to Calculate Standard Free Energy?

The following two example problems outline the steps and information needed in order to calculate the Standard Free Energy.

**Example Problem #1:**

- First, determine the temperature (K). In this example, the temperature (K) is measured to be 95.
- Next, determine the equilibrium constant. For this problem, the equilibrium constant is calculated to be 4.
- Finally, calculate the Standard Free Energy using the formula above:

SFE = -R*T*ln(K)

Inserting the values from above and solving the equation with the imputed values gives:

SFE = -8.314*95*ln(4) = -1094.93 (Joules)

**Example Problem #2: **

Using the same process as example problem 1, we first define the needed variables outlined by the formula. In this case, the values are provide as:

temperature (K) = 5

equilibrium constant = 3

Entering these values into the formula or calculator above gives us:

**SFE = -8.314*5*ln(3) = -45.669 **(Joules)