How to Calculate RTlnK on TI-83

RTlnK is a mathematical formula representing Gibbs energy and equilibrium. When two chemicals react, energy is released. This energy is normally seen through a release of heat. The RTlnK is the formula needed to solve Gibbs energy. Gibbs energy also determines a way to measure all the useful work potentially available during a reaction. In order to simplify the formula, it is often easier to enter the formula into a TI-83 graphing calculator.

Instructions

1. Find the variables of the formula. RTlnK requires you to know R, which is the gas constant, T, which is the temperature in Kelvin, and K, the reaction quotient. R is always 8.314. T varies depending on the temperature of the reaction. K is the atmospheres a liquid has or the molarity for dissolved liquids. In an academic setting, these numbers are normally provided to you.

2. Press "Ln."

3. Enter the reaction quotient.

4. Press ")."

5. Press "Enter."

6. Press "x."

7. Type the temperature. Press "Enter."

8. Press "x."

9. Type "8.314" and press "Enter." This solves the RTlnK formula.

Tips & Warnings

• Before you enter the information into your TI-83 calculator, you should verify that your variables in the formula are accurate. Actually finding the variables are often complicated measurements done by scientists.

References

• URI: Lecture 31
• Wisc Online: TI-83 Log Function