• Gibbs Energy (∆G⦵) is like a crystal ball that tells us if a reaction will go ahead or take a nap under standard conditions.
• Formula time: ∆G⦵ = ∆H⦵ − T∆S⦵
  • ∆H⦵ = Change in enthalpy (heat content)
  • ∆S⦵ = Change in entropy (measure of disorder)
  • T = Absolute Temperature in Kelvin (K)

👉 Use the data booklet for the values of ∆H⦵ and ∆S⦵.

🍦 Real-world example: Imagine you want to buy an ice cream. Your decision (whether to buy or not) depends on two things: how much money you have (enthalpy) and how badly you want that sweet treat (entropy). The weather (temperature) then plays its role; on a hot day, you might be more desperate for ice cream (spontaneous)!

• Endothermic Reactions

  • Absorb heat (feels cold)
  • ∆H⦵ is positive

• Positive Entropy Change

  • More disorder (like a messy bedroom)
  • ∆S⦵ is positive

Temperature's Role in the Dance: 🌡️

When both ∆H⦵ and ∆S⦵ are positive

• High Temperature: The entropy effect dominates. ΔG⦵ becomes negative, so the reaction says, "Let's party!" (spontaneous).
• Low Temperature: The enthalpy effect takes over. ΔG⦵ turns positive, so the reaction goes "Nah, maybe later!" (non-spontaneous).

🎈Fun Fact: The exact temperature where the reaction switches from a “maybe later” to “let’s party” is when ΔG⦵ = 0! Using the equation:

0 = ∆H⦵ − T∆S⦵

When you rearrange it for T:

T = ∆H⦵/∆S⦵

This equation lets you be the genius who figures out the temperature where a reaction becomes spontaneous! 🌟