JAMB/WAEC Chemistry 2027 EP 124 - Gibbs Free Energy + Free JAMB/WAEC Past Questions & Answers

JAMB/WAEC Chemistry EP 124 - Gibbs Free Energy + Free JAMB/WAEC Past Questions & Answers In this lesson, we study Gibbs Free Energy (Gibbs Energy), one of the most important concepts in Chemical Energetics and Thermodynamics. Gibbs Free Energy helps predict whether a chemical reaction will occur spontaneously under constant temperature and pressure. This topic is commonly tested in JAMB, WAEC, NECO, and Post UTME Chemistry. Topics Covered • Gibbs Free Energy • Gibbs Free Energy Change (ΔG) • Spontaneous Reactions • Enthalpy (ΔH) • Entropy (ΔS) • Thermodynamics What Is Gibbs Free Energy? Gibbs Free Energy is the energy available in a system to perform useful work at constant temperature and pressure. The change in Gibbs Free Energy is represented by ΔG. Gibbs Free Energy Equation ΔG = ΔH − TΔS Where: ✔ ΔG = Gibbs Free Energy Change ✔ ΔH = Enthalpy Change ✔ T = Absolute Temperature (Kelvin) ✔ ΔS = Entropy Change Interpretation of Gibbs Free Energy When ΔG is Negative (ΔG is less than 0) ✔ The reaction is spontaneous. ✔ The reaction can occur naturally. When ΔG is Positive (ΔG is greater than 0) ✔ The reaction is non-spontaneous. ✔ External energy is required for the reaction to occur. When ΔG = 0 ✔ The system is at equilibrium. ✔ The forward and reverse reactions occur at the same rate. Factors Affecting Gibbs Free Energy ✔ Enthalpy change (ΔH). ✔ Entropy change (ΔS). ✔ Temperature (T). Applications of Gibbs Free Energy ✔ Predicting spontaneous reactions. ✔ Industrial chemical processes. ✔ Electrochemical cells. ✔ Biochemical reactions. ✔ Thermodynamic calculations. Frequently Tested JAMB Areas 🔥 Gibbs Free Energy 🔥 Gibbs Free Energy Change (ΔG) 🔥 Spontaneous Reactions 🔥 Enthalpy 🔥 Entropy 🔥 Thermodynamics Free JAMB/WAEC Past Questions & Answers 1. Gibbs Free Energy is represented by the symbol? A. ΔH B. ΔS C. ΔG D. ΔT Answer: C 2. If the value of ΔG is negative, the reaction is? A. Non-spontaneous B. Reversible only C. Spontaneous D. Endothermic only Answer: C 3. A reaction is at equilibrium when? A. ΔG is positive B. ΔG is zero C. ΔG is negative D. ΔH is zero Answer: B 4. Which of the following factors affects Gibbs Free Energy? A. Enthalpy B. Entropy C. Temperature D. All of the above Answer: D 5. Gibbs Free Energy is mainly used to predict whether a reaction is? A. Colourful B. Spontaneous C. Radioactive D. Neutral Answer: B Quick Revision Note ✔ Gibbs Free Energy predicts whether a reaction is spontaneous. ✔ ΔG = ΔH − TΔS. ✔ ΔG is less than 0 → Spontaneous reaction. ✔ ΔG is greater than 0 → Non-spontaneous reaction. ✔ ΔG = 0 → Reaction is at equilibrium. ✔ Gibbs Free Energy depends on enthalpy, entropy, and temperature. This lesson is highly recommended for JAMB, WAEC, NECO, and Post UTME candidates preparing for Chemistry examinations. #JAMBChemistry #WAECChemistry #GibbsFreeEnergy #Thermodynamics #ChemicalEnergetics #Enthalpy #Entropy #SpontaneousReaction #ChemistryTutorial #JAMBPastQuestions #WAECPastQuestions #NECOChemistry #O3Schools #StudySmart #ChemistryLessons