Key Thermodynamics and Reaction Concepts

Key Thermodynamics and Reaction Concepts

Heat Energy Processes

• Endothermic: Absorbs heat energy; ΔH>0\Delta H > 0.
• Exothermic: Releases heat energy; ΔH<0\Delta H < 0.

---

Specific Heat Capacity

• Definition: Amount of heat required to raise the temperature of one gram of a substance by 1°C.
• Formula: C=qmΔTC = \frac{q}{m \Delta T}, where qq is heat, mm is mass, and ΔT\Delta T is temperature change.

---

Thermodynamics Overview

• Definition: The study of energy changes in physical and chemical processes.
• First Law of Thermodynamics: Energy is neither created nor destroyed in ordinary chemical reactions and physical changes.

---

Heat and Energy Terms

• Calorie: Heat required to raise the temperature of 1 gram of water by 1°C.
• Enthalpy (ΔH\Delta H): Total energy change during a chemical reaction.
• Heat of Formation (HfH_f): Heat released or absorbed when a compound is formed from its elements.
• Bond Energy: Energy required to break one mole of bonds in the gas phase.

---

Entropy and Disorder

• Entropy (SS): Measure of disorder or randomness in a system.
• Second Law of Thermodynamics: The universe tends toward greater disorder spontaneously.
• Third Law of Thermodynamics: The entropy of a perfect crystalline substance at absolute zero (0 K) is zero.

---

Reaction Kinetics

• Activation Energy: Minimum kinetic energy required for reactants to form products.
• Catalyst: A substance that speeds up a reaction by lowering the activation energy, without being consumed.
• Activated Complex: A high-energy, transitional structure where bonds are simultaneously breaking and forming during a reaction.

These principles form the foundation for understanding chemical reactions, energy exchanges, and the laws governing the behavior of matter and energy.

Quantum Atomic Model and Key Concepts