Chemical Transformations and Discoveries

Matter Classification

• Pure Substance: Composed of only one type of particle, can be an element (simplest form) or a compound (two or more chemically united).
• Mixture: Combination of two or more substances where individual identities are retained, separable via physical methods.
• SOLUTION: Formed by a solute dissolved in a solvent, with properties influenced by the amount of solute.

Thermodynamics

• Focuses on energy conversion and transformation in the universe.
• G: Represents Gibbs free energy, where:
  • G < 0 indicates spontaneous reactions.
  • G > 0 signifies non-spontaneous reactions.
  • G = 0 denotes equilibrium.
• Entropy of a perfect crystalline solid is zero at absolute zero (0 K = -273.15 °C).

Chemical Kinetics

• Studies reaction rates and mechanisms.
• Reaction Rate defined in terms of change in concentration of reactants/products over time.
• Rate Law relates reaction rate to the concentration of reactants raised to a power.

Vapor Pressure and Colligative Properties

• Raoult's Law: The vapor pressure of a solution relies on the amount of nonvolatile solute.
• Boiling Point Elevation: The temperature at which a liquid's vapor pressure equals the external pressure increases with solute addition.
• Freezing Point Depression: The temperature at which a liquid turns to solid decreases with solute presence.
• Osmotic Pressure: The pressure required to stop osmosis, dependent on solute concentration.

Acids & Bases

• Differentiated by properties such as ionic radius, oxidation states, polarizability, and electronegativity.
• Hard acids and bases have small ionic radii and high oxidation states; soft counterparts have larger ionic sizes and lower oxidation states.

Laws of Chemical Equilibrium

• Law of Mass Action: Reaction rate is proportional to the product of reactants' concentrations raised to their coefficients.
• Keq values indicate:
  • Keq = 1: No change (equilibrium).
  • Keq > 1: Forward reaction favored.
  • Keq < 1: Reverse reaction favored.
• Le Chatelier's Principle: If an external stress is applied to a system at equilibrium, the system will shift to counteract that stress.

Periodic Table Overview

• Total of 118 elements organized into 7 periods and 18 groups.
• Group A (Representative Elements): Contain S & P block; each has distinct valence electrons and charges.
• Group B (Transition Elements): Located in the D block, involved in complex bonding.
• Inner Transition Elements: Comprise the Lanthanides and Actinides, found in the F block.

Electron Configuration and Stability

• Octet Rule: Elements strive for eight electrons in their outer shell for stability.
• Valence Electrons: Electrons in the outermost shell determine chemical properties and bonding behavior.

Unique Properties of Specific Elements

• Amphoteric: Elements that can act as either acids or bases.
• Malleable and Ductile: Describe materials that can be shaped easily and drawn into wires, respectively.
• Mercury: Notable as the only liquid metal at room temperature.

Key Experimental Discoveries

• Ernest Rutherford: Discovered the proton and the nucleus through the gold foil experiment, revealing atoms are mostly empty space.
• Niels Bohr: Advanced the planetary model of the atom, primarily using electrons.
• Erwin Schrödinger: Developed the quantum mechanical model implying electron cloud probability distributions rather than fixed orbits.

This quiz explores various chemical processes like sublimation and deionization, alongside key historical discoveries in nuclear chemistry such as Rutherford's gold foil experiment. Understand the transitions of matter and the significant contributions to the field of chemistry.