Course Outline
Check off chapters as you study them, and take each module's test when you're ready. Everything is saved locally in your browser — nothing is uploaded, no account needed.
A note on these questions
These are practice questions written in JEE-style by the Bryn Flow team, covering the correct syllabus concepts for each chapter — they are not reproduced from official past-year papers. Concept notes are written for exam revision specifically, condensed to the reactions, trends, and formulas that actually get tested.
Module 1 — Foundations
1 Some Basic Concepts in Chemistry
The mole is the SI unit for amount of substance: one mole contains Avogadro's number of particles, Nₐ ≈ 6.022 × 10²³. Molarity is moles of solute per litre of solution. The limiting reagent in a reaction is whichever reactant runs out first — it determines the maximum amount of product that can form, regardless of how much excess of the other reactant is present.
Empirical formula gives the simplest whole-number ratio of atoms; molecular formula is a whole-number multiple of the empirical formula matching the actual molar mass.
2 States of Matter
The ideal gas law PV = nRT combines Boyle's law (PV = constant at fixed T), Charles's law, and Avogadro's law. At STP, one mole of an ideal gas occupies 22.4 L. Real gases deviate most from ideal behavior at high pressure and low temperature, where molecular volume and intermolecular attractions (corrected for in the van der Waals equation) become significant.
Liquids are characterized by vapor pressure (which rises with temperature), viscosity, and surface tension — all consequences of intermolecular forces.
3 Atomic Structure
The maximum number of electrons a shell with principal quantum number n can hold is 2n². The azimuthal quantum number (l) determines subshell shape (s, p, d, f). Electrons fill orbitals in order of increasing energy (Aufbau principle), obey the Pauli exclusion principle (no two electrons share all four quantum numbers), and follow Hund's rule (maximum unpaired spins within a subshell before pairing).
Chromium and copper have exceptional configurations ([Ar]3d⁵4s¹ and [Ar]3d¹⁰4s¹ rather than the "expected" filling) because half-filled and fully-filled d-subshells are extra stable.
4 Chemical Bonding and Molecular Structure
VSEPR theory predicts molecular shape from electron pair repulsion — e.g. methane (CH₄) is tetrahedral. Hybridization describes orbital mixing: carbon in CH₄ is sp³ hybridized. Molecular orbital theory gives bond order as (bonding electrons − antibonding electrons) / 2 — higher bond order generally means a shorter, stronger bond.
A molecule's overall polarity depends on both bond polarity and molecular geometry — CO₂ has polar bonds but is nonpolar overall because its linear, symmetric shape cancels the individual dipoles, while NH₃'s pyramidal shape does not cancel and leaves a net dipole.
Module 2 — Physical Chemistry II
5 Chemical Thermodynamics
First law: ΔU = q + w. Enthalpy H = U + PV; the standard enthalpy of formation of an element in its most stable form is defined as zero. Hess's law states that the total enthalpy change for a reaction is independent of the path taken — you can add up steps freely.
Spontaneity at constant temperature and pressure is governed by Gibbs free energy: ΔG = ΔH − TΔS, and a process is spontaneous when ΔG < 0. The second law states that the entropy of the universe increases for any spontaneous process.
6 Solutions
Molality (moles of solute per kg of solvent) is temperature-independent, unlike molarity, which changes slightly with temperature due to volume expansion. Raoult's law: the partial vapor pressure of a component is proportional to its mole fraction in the solution.
Colligative properties (vapor pressure lowering, boiling point elevation, freezing point depression, osmotic pressure) depend on the number of solute particles present, not their chemical identity. The van't Hoff factor i > 1 signals that the solute dissociates in solution (e.g. NaCl → Na⁺ + Cl⁻ gives i ≈ 2).
7 Equilibrium
Le Chatelier's principle: a system at equilibrium shifts to partially counteract any imposed change — increasing pressure on a gas-phase equilibrium shifts it toward the side with fewer moles of gas. Pure water has pH 7 at 25°C. A buffer solution resists pH change when small amounts of acid or base are added, typically made from a weak acid and its conjugate base (or vice versa).
The Bronsted-Lowry definition frames acids as proton donors and bases as proton acceptors — broader than the Arrhenius definition, which requires H⁺/OH⁻ specifically.
Module 3 — Physical Chemistry III
8 Redox Reactions and Electrochemistry
Oxidation is loss of electrons (increase in oxidation number); reduction is gain. In a galvanic (voltaic) cell, oxidation occurs at the anode and reduction at the cathode — the opposite of an electrolytic cell's conventional labeling in terms of spontaneity, though the electrode process definitions stay the same.
The Nernst equation relates cell potential to the standard potential and the reaction quotient, letting you calculate EMF at non-standard concentrations. Faraday's first law of electrolysis: the mass of substance deposited at an electrode is proportional to the quantity of charge passed.
9 Chemical Kinetics
The order of a reaction is determined experimentally from rate data — it cannot be read off the balanced equation's stoichiometry (unlike molecularity, which is a theoretical concept for elementary steps). For a first-order reaction, half-life is independent of initial concentration.
The Arrhenius equation, k = Ae^(−Ea/RT), shows the rate constant increases with temperature. A catalyst speeds up a reaction by providing an alternative pathway with lower activation energy, without being consumed itself.
10 Classification of Elements and Periodicity in Properties
Across a period (left to right), atomic radius generally decreases and ionization energy generally increases, as increasing nuclear charge pulls electrons in more tightly. Electronegativity follows the same across-period increase, but decreases down a group as atomic radius grows and the outer electrons are held less tightly.
The first member of a group often behaves anomalously compared to the rest — lithium, for instance, differs from the other alkali metals in several properties, more closely resembling magnesium (a "diagonal relationship").
Module 4 — Inorganic Chemistry
11 p-Block Elements
The inert pair effect explains why heavier p-block elements (like Tl, Pb, Bi) increasingly favor oxidation states two less than the group's maximum — the ns² electrons become reluctant to participate in bonding. Carbon's allotropes include diamond (each carbon sp³-bonded to 4 others, extremely hard) and graphite (sp² layers, soft, conducts electricity).
Noble gases, once believed totally inert, do form compounds — most notably several xenon fluorides (XeF₂, XeF₄) and xenon oxides. Boron shows a diagonal relationship with silicon, sharing several chemical similarities despite being in different groups.
12 d- and f-Block Elements
Transition metals commonly show variable oxidation states because the (n−1)d and ns orbitals are close in energy, and they often form colored compounds due to d-d electronic transitions. Their ability to adopt multiple oxidation states and form complexes with reactants makes many transition metals effective catalysts.
Lanthanide contraction — the steady decrease in atomic/ionic radii across the lanthanide series — happens because the poorly-shielding 4f electrons let effective nuclear charge increase steadily, and it has knock-on effects on the properties of the elements that follow the lanthanides in the periodic table.
13 Coordination Compounds
Coordination number is the number of ligand donor atoms directly bonded to the central metal ion. Ligands can be monodentate (one donor atom) or polydentate — EDTA, for example, is hexadentate, binding through six donor atoms at once.
Crystal field theory explains the color and magnetic behavior of coordination complexes by describing how the ligand field splits the metal's d-orbital energies. Geometrical isomerism (like cis/trans arrangements) is common in square planar and octahedral complexes.
14 General Principles of Extraction of Metals
Calcination heats an ore in the absence (or limited supply) of air, typically to drive off volatile impurities like water or CO₂; roasting heats it in the presence of air, often to convert sulfide ores to oxides. An Ellingham diagram plots the thermodynamic feasibility of reducing a metal oxide at different temperatures, guiding the choice of reducing agent.
Highly reactive metals (Na, Al) are extracted by electrolytic reduction, since no common chemical reducing agent is strong enough. The thermite process uses aluminum's strong affinity for oxygen to reduce iron oxide to molten iron.
Module 5 — Organic Chemistry I
15 Basic Principles of Organic Chemistry & Purification
The inductive effect is a permanent electron-pulling or -donating effect transmitted through sigma bonds; resonance stabilizes a structure by delocalizing electron density across multiple atoms. Carbocation stability follows tertiary > secondary > primary, largely due to hyperconjugation and the inductive effect of surrounding alkyl groups.
Common purification techniques: distillation separates by boiling point, crystallization by differing solubility, and chromatography by differential adsorption or partition between a stationary and mobile phase.
16 Hydrocarbons
Markovnikov's rule: when HX adds across an unsymmetrical alkene, the hydrogen preferentially bonds to the carbon that already has more hydrogens (equivalently, X goes to the more substituted carbon, forming the more stable carbocation intermediate). Benzene favors electrophilic substitution over addition, since substitution preserves its aromatic stability.
Hückel's rule: a planar, fully conjugated ring is aromatic if it has (4n+2) π electrons. Terminal alkynes have a mildly acidic hydrogen, since the sp-hybridized carbon holds the bonding electrons closer to the nucleus, stabilizing the resulting anion.
17 Organic Compounds Containing Halogens
An SN2 reaction proceeds via a single-step backside attack, causing inversion of configuration at the carbon center, and is favored by primary halides (least steric hindrance). An SN1 reaction proceeds through a carbocation intermediate and is favored by tertiary halides, which form more stable carbocations.
Grignard reagents (RMgX) are powerful nucleophiles that react with carbonyl compounds (aldehydes, ketones, esters) to build alcohols with new C–C bonds — one of organic chemistry's most useful carbon-chain-extension tools.
Module 6 — Organic Chemistry II
18 Organic Compounds Containing Oxygen
Phenol is considerably more acidic than a simple alcohol because the resulting phenoxide ion is resonance-stabilized by the aromatic ring — and carboxylic acids are more acidic still, since the carboxylate ion is even better resonance-stabilized (with two equivalent resonance structures).
Aldehydes are generally more reactive than ketones toward nucleophilic addition, due to less steric hindrance and a weaker electron-donating effect from only one alkyl group. The Cannizzaro reaction — simultaneous oxidation and reduction of two aldehyde molecules under strong base — only occurs for aldehydes lacking an alpha-hydrogen (so they can't undergo the competing aldol reaction).
19 Organic Compounds Containing Nitrogen
Aliphatic amines are generally more basic than aromatic amines like aniline, because in aniline the nitrogen's lone pair delocalizes into the aromatic ring, making it less available to accept a proton. A commonly taught basicity ordering is methylamine > ammonia > aniline.
Diazonium salts are versatile synthetic intermediates — reactions like the Sandmeyer reaction use them to install a wide range of substituents onto an aromatic ring. The Hofmann bromamide degradation converts an amide into a primary amine with one fewer carbon atom.
20 Biomolecules, Polymers & Chemistry in Everyday Life
Proteins are polymers of amino acids joined by peptide bonds. DNA stores genetic information; RNA (mRNA, tRNA, rRNA) carries out protein synthesis. Polymers form either by addition (monomers with double bonds link directly, e.g. polyethylene) or condensation (monomers join with loss of a small molecule like water, e.g. nylon-6,6).
In medicinal chemistry, antibiotics work through selective toxicity — killing or inhibiting microorganisms while leaving host cells largely unharmed, typically by targeting structures or processes (like bacterial cell walls) that human cells don't share.