12th Chemistry Question Bank Review

This set of vocabulary flashcards covers key terms, definitions, and chemical principles identified in the 12th Standard Chemistry Question Bank from the Maharashtra State Council of Educational Research and Training.

Molecular solids

Types of solids that contain molecules as their constituent particles.

Bravais lattices

The distinct lattice types which uniquely fill three-dimensional space; for example, the orthorhombic system contains 4 of these.

Octahedral void

A void in a crystal structure that is surrounded by $6$ spheres.

Amorphous solid

A solid that lacks a long-range periodic order of its constituent particles, such as tar.

Schottky defect

A point defect in an ionic crystal where a paired cation-anion vacancy occurs.

Frenkel defect

A point defect in a crystal lattice where an atom or ion leaves its own lattice site vacant and occupies an interstitial site; it has no effect on the density of the substance.

Diamagnetic substances

Substances that are weakly repelled by a magnetic field because all electrons are paired.

Henry's Law

States that the solubility of a gas in a liquid is directly proportional to the pressure of the gas above the liquid.

Colligative properties

Properties of solutions that depend only on the number of solute particles and not on their chemical nature.

Raoult's Law

States that the partial vapour pressure of any volatile constituent of a solution is equal to the vapour pressure of the pure constituent multiplied by its mole fraction in the solution.

Isotonic solutions

Two or more solutions having the same osmotic pressure at a given temperature.

Cryoscopic constant

The freezing point depression constant, also known as $K_f$, expressed in $K\,kg\,mol^{-1}$.

Conjugate acid-base pair

A pair of species in a reaction that differ only by a single proton, such as $H_3O^{+}$ and $H_2O$.

Buffer solution

A solution that resists drastic changes in $pH$ upon the addition of small amounts of strong acid or base.

Solubility product ($K_{sp}$)

The equilibrium constant for the dissolution of a sparingly soluble ionic compound in water.

Amphoteric nature of water

The ability of water to act as both an acid and a base, as explained by the Bronsted-Lowry theory.

Intensive property

A physical property of a system that does not depend on the system size or the amount of material in the system, such as temperature or pressure.

Extensive property

A physical property that depends on the amount of matter in a specimen, such as mass or volume.

Isothermal process

A thermodynamic process in which the temperature of the system remains constant ($\Delta T = 0$).

Isochoric process

A thermodynamic process in which the volume remains constant ($\Delta V = 0$).

Hess's Law

States that the total enthalpy change for a chemical reaction is independent of the pathway taken, provided the initial and final states are the same.

Kohlrausch Law

Commonly known as the law of independent migration of ions, it states that at infinite dilution, each ion migrates independently of its co-ion and contributes to the total molar conductivity.

Salt bridge

A device used to connect the oxidation and reduction half-cells of a galvanic cell; it typically contains an inert electrolyte like $KCl$ or $KNO_3$.

Order of reaction

The sum of indices of the concentrations of reactants in the rate law expression.

Molecularity

The number of reactant molecules taking part in an elementary reaction.

Pseudo first order reaction

A reaction that is expected to be of higher order but follows first-order kinetics due to one reactant being in large excess.

Chalcogens

The name given to elements in Group 16 of the periodic table.

Interhalogen compounds

Compounds formed by the reaction of two different halogens among themselves.

Lanthanoid contraction

The steady decrease in the atomic and ionic radii of the lanthanoid elements with increasing atomic number.

Transuranium elements

Elements with atomic numbers greater than $92$ (uranium).

Ambidentate ligand

A ligand that has two different donor atoms and can coordinate to the metal ion through either of the two atoms, such as cyanide ion ($CN^{-}$).

Effective Atomic Number (EAN)

The total number of electrons surrounding the central metal ion in a complex, calculated to determine the stability of the compound.

Homoleptic complex

A coordination complex where the central metal atom is bound to only one type of ligand.

Heteroleptic complex

A coordination complex where the central metal atom is bound to more than one type of ligand.

Optical activity

The property of a chiral molecule that allows it to rotate the plane of polarized light.

Grignard reagent

Alkyl magnesium halide ($R-Mg-X$), an organometallic compound used in organic synthesis.

Dehydrohalogenation

An elimination reaction in which a hydrogen halide is removed from a substrate, typically an alkyl halide, to form an alkene.

Zwitterion

A dipolar ion formed by an amino acid where the carboxylic group loses a proton and the amino group gains a proton.

Peptide bond

A covalent chemical bond formed between two amino acid molecules when the carboxyl group of one reacts with the amino group of the other.

Homopolymer

A polymer derived from a single species of monomer.

Copolymer

A polymer derived from more than one species of monomer.

Vulcanization

A chemical process for converting natural rubber into more durable materials by adding sulfur or other equivalent curatives.

Atom economy

A principle of green chemistry that measures the efficiency of a chemical reaction by the percentage of reactant atoms that end up in the desired product.

Sustainable development

Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.