Karnataka II PUC Chemistry Question Bank (Subject Code: 34)

Comprehensive vocabulary flashcards covering key definitions, principles, reagents, named reactions, and biomolecules from the Karnataka II PUC Chemistry Question Bank syllabus.

Saturated Solution

A solution that contains the maximum amount of solute that can be dissolved in a given quantity of solvent at a specified temperature and pressure.

Molality ($m$)

A temperature-independent concentration unit defined as the number of moles of solute present per kilogram of solvent ($\text{mol}\,\text{kg}^{-1}$).

Henry's Law

The law stating that at a constant temperature, the solubility or partial pressure of a gas in the vapour phase ($p$) is directly proportional to the mole fraction of the gas ($x$) in the solution: $p = K_{\text{H}} x$.

Raoult's Law

The law stating that for a solution of volatile liquids, the partial vapour pressure of each volatile component is equal to the product of its vapour pressure in the pure state and its mole fraction in solution ($p_1 = x_1 p_1^0$).

Azeotrope (Azeotropic Mixture)

A constant-boiling binary liquid mixture having the same composition in both the liquid and vapour phases, which distils at a constant temperature without undergoing separation by fractional distillation.

Colligative Properties

Properties of dilute solutions that depend strictly on the total number of solute particles present in the solution, rather than on the chemical nature or identity of the solute.

Osmotic Pressure ($\Pi$)

The excess hydrostatic pressure that must be applied to the solution side across a semipermeable membrane to prevent the inward osmosis of pure solvent.

Reverse Osmosis

A water-purification process in which an external pressure exceeding the osmotic pressure ($P_{\text{applied}} > \Pi$) is exerted on a solution, forcing pure solvent molecules to migrate backward through a semipermeable membrane into the pure solvent chamber.

van 't Hoff Factor ($i$)

The ratio between the experimentally measured colligative property and the calculated theoretical value, where $i > 1$ signifies solute dissociation, $i < 1$ denotes association, and $i = 1$ indicates no association or dissociation.

Standard Hydrogen Electrode (SHE)

A primary reference half-cell consisting of a platinum wire coated with platinum black dipping into a $1\,\text{M}$ $\text{H}^+$ solution at $298\,\text{K}$ with pure $\text{H}_2$ gas bubbled at $1\,\text{bar}$ (or $1\,\text{atm}$), assigned an arbitrary electrode potential of $0.00\,\text{V}$.

Nernst Equation

An equation relating the electrode potential ($E$) or cell potential ($E_{\text{cell}}$) to the standard electrode potential ($E^0$), temperature, and ionic concentrations of the reacting chemical species.

Molar Conductivity ($\Lambda_m$)

The electrolytic conductance of a volume of solution containing exactly one mole of dissolved electrolyte placed between two parallel electrodes separated by a distance of $1\,\text{cm}$.

Kohlrausch's Law of Independent Migration of Ions

The principle stating that the limiting molar conductivity of an electrolyte ($\Lambda_m^0$) can be expressed as the sum of the individual limiting molar conductivities contributed by its constituent cations and anions at infinite dilution.

Faraday's First Law of Electrolysis

The law stating that the mass of a substance deposited or liberated at any electrode during electrolysis is directly proportional to the total electrical charge ($Q$) passed through the electrolyte ($w \propto Q$).

Fuel Cell

A galvanic cell that converts the chemical energy derived from the combustion of fuels (such as hydrogen, methane, or methanol) directly into electrical energy via continuous feed of reactants.

Corrosion

An electrochemical process that slowly degrades a refined metal into its oxide, sulphide, or carbonate due to chemical redox reactions with atmospheric oxygen and moisture.

Rate Law

A mathematical expression representing the rate of a chemical reaction in terms of the molar concentrations of reactants, with each term raised to an experimentally determined power.

Order of a Reaction

The sum of the exponents of the concentration terms of the reacting species in the experimentally determined differential rate law equation.

Molecularity of a Reaction

The total number of reacting atoms, ions, or molecules that must collide simultaneously in an elementary step to bring about a chemical reaction.

Pseudo First-Order Reaction

A bimolecular or multi-reactant reaction that follows first-order chemical kinetics because one of the participating reactants is present in large excess (e.g., the acid-catalysed hydrolysis of ethyl acetate or inversion of cane sugar).

Half-Life Period ($t_{1/2}$)

The time duration required for the concentration of a reactant to be reduced to exactly one-half of its initial value.

Activation Energy ($E_a$)

The minimum excess energy that colliding reactant molecules must acquire over their ground-state energy to form an activated complex and convert into products.

Collision Frequency ($Z_{AB}$)

The total number of binary collisions between reacting molecules $A$ and $B$ occurring per second per unit volume of the reaction mixture.

Transition Elements

Elements possessing incompletely filled $d$ subshells in their ground elementary state or in any of their stable common oxidation states.

Lanthanoid Contraction

The steady, gradual decrease in atomic and ionic radii of the trivalent lanthanoid ions ($\text{Ln}^{3+}$) from Lanthanum ($Z = 57$) to Lutetium ($Z = 71$), caused by the poor shielding effect of the inner $4f$ electrons.

Interstitial Compounds

Non-stoichiometric, chemically inert compounds formed when small non-metal atoms such as $\text{H}$, $\text{C}$, or $\text{N}$ are trapped within the interstitial spaces of a transition metal crystal lattice.

Mischmetall

A pyrophoric alloy composed of approximately $95\%$ lanthanoid metals, about $5\%$ iron, and trace quantities of sulphur, carbon, calcium, and aluminium.

Chelating Ligand

A di- or polydentate ligand that coordinates simultaneously to a single central metal atom or ion using two or more donor atoms to form a stable ring structure.

Ambidentate Ligand

A unidentate ligand containing two different donor atoms that can coordinate to the central metal atom through either one of the donor sites (e.g., $\text{NO}_2^-$ or $\text{SCN}^-$).

Homoleptic Complex

A coordination complex in which the central metal ion is coordinated to only one kind of donor ligand group.

Spectrochemical Series

An experimentally determined arrangement of common ligands in order of their increasing crystal field splitting energy ($\Delta_o$) capability.

Vicinal Dihalides

Dihalogen-substituted hydrocarbons in which two halogen atoms are bonded to two adjacent (vicinal) carbon atoms.

Geminal Dihalides

Dihalogen-substituted organic compounds in which two halogen atoms are attached to the exact same carbon atom.

Finkelstein Reaction

The halogen-exchange synthesis of alkyl iodides achieved by treating alkyl chlorides or bromides with sodium iodide ($\text{NaI}$) in dry acetone.

Swarts Reaction

The preparation of alkyl fluorides by heating alkyl chlorides or bromides in the presence of heavy metallic fluorides such as $\text{AgF}$, $\text{Hg}_2\text{F}_2$, $\text{CoF}_2$, or $\text{SbF}_3$.

Sandmeyer Reaction

The chemical conversion of a diazonium salt into a chloroarene or bromoarene by treatment with freshly prepared cuprous chloride ($\text{Cu}_2\text{Cl}_2$) or cuprous bromide ($\text{Cu}_2\text{Br}_2$) in the presence of the corresponding halogen acid.

Zaitsev's (Saytzeff's) Rule

The dehydrohalogenation rule stating that in elimination reactions, the major alkene product is the one that has the greater number of alkyl substituents attached to the double-bonded carbon atoms.

Enantiomers

Optical stereoisomers that are non-superimposable mirror images of each other and rotate plane-polarized light in equal magnitudes but opposite directions.

Racemic Mixture

An equimolar mixture of dextrorotatory and laevorotatory enantiomers that exhibits zero net optical rotation due to external compensation.

Lucas Reagent

A solution consisting of an equimolar mixture of concentrated hydrochloric acid and anhydrous zinc chloride ($\text{conc. HCl} + \text{anh. ZnCl}_2$), used to classify primary, secondary, and tertiary alcohols based on the appearance of turbidity.

Kolbe's Reaction

The electrophilic substitution reaction in which sodium phenoxide is heated with carbon dioxide ($\text{CO}_2$) followed by acidification to produce 2-hydroxybenzoic acid (salicylic acid).

Reimer-Tiemann Reaction

The reaction of phenol with chloroform in the presence of aqueous sodium hydroxide at elevated temperatures to introduce an aldehyde ($-\text{CHO}$) group ortho to the phenolic hydroxyl group, yielding salicylaldehyde.

Williamson Ether Synthesis

An $\text{S}_{\text{N}}2$ laboratory method for the synthesis of symmetrical and unsymmetrical ethers by reacting an alkyl halide with a sodium alkoxide ($\text{R-X} + \text{R'-ONa} \rightarrow \text{R-O-R'} + \text{NaX}$).

Rosenmund Reduction

The selective catalytic hydrogenation of an acyl chloride to an aldehyde using hydrogen gas over palladium supported on barium sulphate ($\text{Pd/BaSO}_4$).

Stephen Reaction

The reduction of alkyl or aryl nitriles with stannous chloride and hydrochloric acid ($\text{SnCl}_2 + \text{HCl}$) to form an imine intermediate, which yields the corresponding aldehyde upon acid hydrolysis.

Etard Reaction

The mild oxidation of toluene to benzaldehyde using chromyl chloride ($\text{CrO}_2\text{Cl}_2$) in carbon disulphide or $\text{CCl}_4$ to form a brown chromium complex, followed by aqueous hydrolysis.

Clemmensen Reduction

The chemical deoxygenation of the carbonyl group of an aldehyde or ketone to a methylene ($-\text{CH}_2-$) group using zinc amalgam and concentrated hydrochloric acid ($\text{Zn-Hg} + \text{conc. HCl}$).

Wolff-Kishner Reduction

The conversion of an aldehyde or ketone into an alkane by heating its hydrazone intermediate with potassium hydroxide in a high-boiling solvent such as ethylene glycol.

Aldol Condensation

The base-catalysed self-condensation of aldehydes or ketones having at least one $\alpha$-hydrogen atom to form a $\beta$-hydroxy aldehyde or ketone, which upon heating undergoes dehydration to an $\alpha,\beta$-unsaturated carbonyl compound.

Cannizzaro Reaction

The redox disproportionation of aldehydes lacking an $\alpha$-hydrogen atom upon treatment with concentrated alkali, producing one molecule of an alcohol and one molecule of a carboxylic acid salt.

Hell-Volhard-Zelinsky (HVZ) Reaction

The substitution reaction wherein carboxylic acids having $\alpha$-hydrogen atoms are halogenated at the $\alpha$-position by treatment with chlorine or bromine in the presence of red phosphorus, followed by hydrolysis to yield $\alpha$-halocarboxylic acids.

Gabriel Phthalimide Synthesis

A synthetic method used for the exclusive preparation of primary aliphatic amines by nucleophilic attack of potassium phthalimide on a primary alkyl halide followed by alkaline hydrolysis.

Hoffmann Bromamide Degradation Reaction

The conversion of a primary acid amide into a primary amine containing one fewer carbon atom by heating the amide with bromine in an aqueous or ethanolic solution of sodium hydroxide.

Carbylamine Reaction (Isocyanide Test)

A diagnostic chemical test for primary aliphatic and aromatic amines, in which heating the amine with chloroform and alcoholic potassium hydroxide produces an intensely foul-smelling isocyanide (carbylamine).

Hinsberg's Reagent

Benzenesulphonyl chloride ($\text{C}_6\text{H}_5\text{SO}_2\text{Cl}$), an organic reagent used to distinguish between primary, secondary, and tertiary amines based on the alkali solubility of the resulting sulphonamides.

Anomers

Stereoisomeric cyclic forms of a monosaccharide that differ in spatial configuration only at the hemiacetal or hemiketal carbonyl carbon atom (referred to as the anomeric carbon).

Glycosidic Linkage

The covalent ether (oxide) linkage that joins two monosaccharide rings together through an oxygen atom with the elimination of a water molecule.

Invert Sugar

An equimolar mixture of glucose and fructose produced by the hydrolysis of dextrorotatory sucrose, which exhibits overall laevorotation because the laevorotation of fructose ($-92.4^\circ$) exceeds the dextrorotation of glucose ($+52.5^\circ$).

Zwitterion

An internal, dipolar, electrically neutral ionic form of an amino acid produced by the intramolecular transfer of a proton from the carboxylic acid group ($-\text{COOH}$) to the basic amino group ($-\text{NH}_2$).

Peptide Linkage

An amide linkage ($-\text{CO}-\text{NH}-$) formed between the carboxyl group of one $\alpha$-amino acid molecule and the amino group of another via the condensation loss of a water molecule.

Denaturation of Proteins

The loss of biological activity of a native protein caused by physical (heat) or chemical (pH) stress that disrupts secondary and tertiary structures while leaving the primary covalent peptide backbone intact.