Essential Chemistry Principles and Reaction Mechanisms

Posted on Mar 12, 2026 in Chemistry

Electrochemistry and Faraday’s Laws

Electrochemical (Galvanic) Element: A two-electrode system where electric current is generated via a chemical reaction.
Faraday’s First Law: The mass of a substance deposited at an electrode is proportional to the amount of electricity passed through the solution.
Faraday’s Second Law: When the same amount of electricity passes through different electrolytes, the masses of the separated substances are proportional to their equivalent masses.
Electrolysis of Table Salt (Aqueous): Produces NaOH, H₂, and Cl₂.
pH Calculation: The pH of 0.001 M NH₃ is approximately 3.

Hybridization: The hybrid state of atoms changes during addition reactions.
1-Butene to 2-Butene: Can be achieved via two consecutive reactions using hydrogen chloride and an alcoholic potassium-based solution.
Acidity of Alcohols: Acidity decreases as the number of carbon residues increases (CH₃OH > CH₃CH₂OH > … > (CH₃)₃COH) due to electron density withdrawal from the OH group.
Imidazole: A 1,3-diazole with aromatic properties. It can be nitrated and sulfonated at the 4th and 5th positions.
Fatty Amines: Obtained via Hoffman’s method by heating halogenated alkanes with an alcoholic ammonia solution.
Aldol Condensation: Acetaldehyde is a compound that can participate in this reaction.
Pyrrole: A 5-atom aromatic ring. Its aromaticity is due to a delocalized sextet of electrons (P-electrons from double bonds and the N-atom’s lone pair).

Non-electrolytes: Covalently bonded substances with weak polar or non-polar connections.
Properties: Dilute solutions of non-electrolytes have properties that depend only on concentration, not the nature of the solute.
Van’t Hoff’s Law: Expressed as π = C × R × T.
Hydrolysis of Salts: A reversible interaction between salt ions and water, altering the ratio of H⁺ and OH⁻ ions.
Henry’s Law: C = kP, where concentration is proportional to gas pressure.
Molarity vs. Normality: Molarity is moles per liter; Normality is equivalents per liter.

Electrode Definition: A conductor that, when placed in an electrolyte, develops an electric potential.
Redox Reactions: Direction is determined by the system’s tendency toward maximum stability (equilibrium).
Molecularity vs. Reaction Order: Molecularity refers to the number of molecules in a simple reaction; order is an empirical value derived from concentration changes.
Reaction Rate Factors: Influenced by the nature of reactants, temperature, and concentration.
Buffer Solutions: Mixtures that maintain a constant pH. Buffer capacity measures the amount of strong acid or base required to change the pH by 1 unit.

Antibonding Orbitals: Electrons in these orbitals decrease bond strength and increase reactivity.
Bond Order: Calculated as (Bonding e⁻ – Antibonding e⁻) / 2.
Sigma (σ) vs. Pi (π) Bonds: σ-bonds (head-on overlap) are stronger than π-bonds (side-on overlap).
Ice Structure: Water molecules in ice are held together by hydrogen bonds.
Coordination Compounds: Characterized by donor-acceptor bonds.
Hemes: Porphyrin complexes with Fe²⁺, such as hemoglobin, which transports oxygen.