Revision Essentials
Curated 1-mark & 2-mark definitions based on 10-year CBSE analysis. π―
Focus 200% on these: Kohlrausch's Law, Lanthanoid Contraction, Zwitterion structure, Pseudo 1st Order, and Ideal vs Non-Ideal deviations.
π‘ Exam Hack: The "Exact Word" Policy
CBSE examiners look for specific keywords like "infinite dilution", "per unit volume", or "non-volatile". Using these ensures a full 1 mark even if the grammar is slightly off!
Solutions Definitions
Number of moles of solute dissolved in one litre (1L) of solution.
Number of moles of solute dissolved in one kilogram (1kg) of solvent.
For a solution of volatile liquids, the partial vapour pressure of each component is directly proportional to its mole fraction.
A solution that obeys Raoult's law over the entire range of concentrations and shows no change in enthalpy or volume on mixing (\(\Delta H_{\text{mix}} = 0\)).
Binary mixtures having the same composition in liquid and vapour phase and boil at a constant temperature.
Properties that depend only on the number of solute particles and not on their nature.
Electrochemistry Definitions
Conductivity of all the ions produced by dissolving one mole of an electrolyte in a solution.
At infinite dilution, molar conductivity of an electrolyte can be represented as the sum of individual contributions of the anion and cation.
A reference electrode used to measure standard electrode potentials, assigned a potential of exactly 0.00 V at all temperatures.
Galvanic cells that are designed to convert the energy of combustion of fuels directly into electrical energy.
Slow coating of the surfaces of metallic objects with oxides or other salts of the metal due to interaction with enviornment.
Chemical Kinetics
Sum of powers of the concentration of the reactants in the rate law expression.
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Number of reacting species taking part in an elementary reaction, which must collide simultaneously.
Rate of reaction when the concentration of each reactant is unity (1 M).
Minimum extra energy required by a reactant molecule to form an intermediate (activated complex).
Reactions which are not truly of first order but under certain conditions behave as first order (e.g., Inversion of cane sugar).
Surface Chemistry (Definitions Goldmine)
Accumulation of molecular species at the surface rather than in the bulk of a solid or liquid.
Scattering of a beam of light by colloidal particles when passed through a colloidal solution.
Process of converting a fresh precipitate into colloidal sol by shaking it with dispersion medium in presence of electrolyte.
Greater the valence of the flocculating ion added, the greater is its power to cause precipitation.
d & f Block Elements
Steady decrease in atomic and ionic radii of lanthanoid elements with increasing atomic number due to poor shielding of 4f electrons.
Elements which have incompletely filled d-orbitals in its ground state or in any of its oxidation states.
An alloy which consists of a lanthanoid metal (~ 95%) and iron (~ 5%) and traces of S, C, Ca and Al.
Coordination Compounds
The central metal atom and the ligands that are directly attached to it, enclosed in square brackets.
A ligand which can ligate through two different atoms (e.g. \(NO_2^-\) - it can bind through N or O).
When a di- or polydentate ligand binds to a metal ion, it forms a ring-like structure; this complex is more stable than others.
Haloalkanes & Haloarenes
Nucleophiles that possess two nucleophilic centers and can attack from either side (e.g. \(CN^-\), \(NO_2^-\)).
Property of non-superimposability of an object on its mirror image.
Stereoisomers related to each other as non-superimposable mirror images.
Alcohols, Phenols & Ethers
Process of making ethyl alcohol unfit for drinking by adding small amounts of poisonous substances like methanol or copper sulphate.
Treatment of phenol with chloroform in the presence of sodium hydroxide to introduce an aldehyde group at the ortho position.
Aldehydes & Ketones
Self-addition of aldehydes or ketones having \(\alpha\)-hydrogen in the presence of dilute alkali to form \(\beta\)-hydroxy carbonyls.
Redox reaction of aldehydes which lack \(\alpha\)-hydrogen on treatment with concentrated alkali.
Carboxylic Acids
Reaction of carboxylic acids having \(\alpha\)-hydrogen with \(Cl_2\) or \(Br_2\) in presence of red phosphorus to form \(\alpha\)-halo acids.
Elimination of a molecule of carbon dioxide from a carboxylic acid to form a hydrocarbon.
Amines
A method for the preparation of primary aliphatic amines by the reaction of phthalimide with alkyl halides followed by hydrolysis.
Benzenesulphonyl chloride, used for distinguishing between \(1^\circ\), \(2^\circ\) and \(3^\circ\) amines.
Treatment of an amide with bromine and aqueous NaOH to form a primary amine with one carbon atom less.
Biomolecules (Mark Scoring)
A dipolar ion formed when the carboxylic group loses a proton and amino group accepts it from within the molecule.
The \(βCONHβ\) bond formed between two amino acid units through elimination of a water molecule.
Cyclic monosaccharides that differ in configuration only at the hemiacetal or hemiketal carbon (C-1).
Loss of biological activity of protein due to disruption of secondary and tertiary structures by physical or chemical change.
Chemical Distinction Tests (3 Mark Guaranteed)
Distinguishes 1Β°, 2Β°, 3Β° Alcohols. 3Β° alcohols give turbidity immediately, 2Β° in 5 mins, 1Β° only on heating.
Distinguishes Aldehydes from Ketones. Aldehydes give **Silver Mirror** with Tollens' and **Red ppt** with Fehling's (except Benzaldehyde).
Identifies **Methyl Ketones** (\(CH_3CO-\)) and ethanol/2-propanol. Gives **Yellow ppt** (\(CHI_3\)).
Only for **Primary Amines** (Aliphatic/Aromatic). Gives **foul-smelling** isocyanides.
Organic Conversion Hacks
Use \(KCN\) followed by hydrolysis (\(\to\) acid) or reduction (\(\to\) amine). Wurtz reaction is also an option for alkanes.
Use **Hofmann Bromamide Degradation** (Amide \(\to\) Amine) or **Decarboxylation** (Acid \(\to\) Alkane).
Convert everything to **Benzene Diazonium Chloride** (\(C_6H_5N_2^+Cl^-\)) to reach phenol, haloarenes, or benzonitrile easily.