Complete notes: Units 9–16 | Equilibrium, Acids/Bases, Organics, Biochemistry, Environment, Water, Metallurgy & more.
Reversible: Products can revert to reactants under same conditions (e.g., N₂ + 3H₂ ⇌ 2NH₃). Irreversible: Proceed only one direction (e.g., combustion). Most reactions do not go to completion due to reverse reaction establishing equilibrium.
Dynamic: Forward and reverse rates equal, macroscopic properties constant. Static: No forward/back movement (rare in chemistry).
Rate of reaction ∝ active mass (concentration). For aA + bB ⇌ cC + dD, equilibrium constant Kc = [C]c[D]d / [A]a[B]b.
Value indicates extent of reaction. Large K → products favored; small K → reactants favored.
When forward rate equals reverse rate, after some time, concentrations become constant → dynamic equilibrium.
Higher active mass (molar concentration) → higher collision frequency → increased reaction rate.
Compare reaction quotient Q with K: Q<K → forward; Q>K → reverse; Q=K → equilibrium.
Macroscopic characteristics: Forward reaction decreases reactants, reverse increases products; at dynamic equilibrium, no net change, color/pressure constant.
Acid: H⁺ donor in water (HCl → H⁺ + Cl⁻). Base: OH⁻ donor (NaOH → Na⁺ + OH⁻).
Requires aqueous medium; fails for non-aqueous or gas-phase (e.g., NH₃ in benzene).
Acid = proton donor; Base = proton acceptor. Conjugate pairs: HCl/Cl⁻, NH₄⁺/NH₃.
Lewis acid = electron pair acceptor (e.g., BF₃, H⁺). Lewis base = electron pair donor (NH₃, H₂O).
H⁺ has empty 1s orbital → accepts electron pair from bases.
Fertilizers, batteries, steel pickling, detergents, dehydrating agent.
pH = 7 at 25°C. pH = -log[H₃O⁺].
Measure of acidity/basicity: pH<7 acidic, =7 neutral, >7 basic.
Substances changing color with pH (e.g., phenolphthalein, methyl orange). Used to determine endpoint.
Ionic compounds from acid-base neutralization: NaCl, Na₂CO₃.
NaCl: food, de-icing; NaHCO₃: baking; KNO₃: fertilizer.
Sodium silicate: adhesives, fireproofing; CaCl₂: de-icing, drying agent; CaO (lime): cement, flue gas treatment.
Acidic salts contain replaceable H (NaHSO₄). Basic salts contain OH (Mg(OH)Cl).
Organic compounds only from living organisms (disproved by Wöhler’s urea synthesis).
Compounds derived from plants/animals containing “vital force”.
Ability of carbon to form long chains/bonds with itself.
Glucose: C₆H₁₂O₆.
-OH (hydroxyl group).
Fossilized plant matter under high pressure/temperature over millions of years.
Atom/group determining chemical properties: aldehyde (-CHO), ketone (>C=O), carboxylic acid (-COOH).
Valence electrons shown as dots/crosses around atoms (e.g., H₂O).
Carbon atoms in straight/branched chains (e.g., butane).
Cyclic but not aromatic (e.g., cyclohexane).
Pyridine, furan (contains O, N in ring).
Same formula, different structure. Pentane: 3 isomers (n-pentane, isopentane, neopentane).
Fuel for heating, electricity, raw material for hydrogen & fertilizers.
Compounds only C and H (alkanes, alkenes, alkynes, aromatics).
Open: aliphatic (linear/branched); Closed: cyclic (cycloalkanes, aromatic).
Saturated: single C–C bonds (alkanes). Unsaturated: double/triple bonds (alkenes, alkynes).
Latin: parum affinis = little reactivity.
Addition of H₂ (Ni catalyst) → alkanes.
Ethane: ethylene production, refrigerant. Ethene: ripening fruits, polyethylene plastic.
Study of chemical processes in living organisms.
Starch, cellulose: high molecular weight, insoluble in water, store energy/structural.
Single sugar unit (glucose, fructose), sweet, reducing agents, soluble.
H₂N–CHR–COOH; building blocks of proteins.
Essential: cannot be synthesized by body (must be diet); non-essential: body can produce.
Vitamin A: carrots, liver → vision/immunity. Vitamin D: sunlight, fish → calcium absorption.
Energy source (glucose), structural (cellulose).
Ghee: saturated fats (solid); oils: unsaturated (liquid at room temp).
Stores genetic information, codes for proteins.
Fat-soluble (A, D, E, K) and water-soluble (B-complex, C).
mRNA carries genetic code from DNA to ribosomes for protein synthesis.
Troposphere, stratosphere, mesosphere, thermosphere, exosphere.
Atmosphere = gaseous envelope; environment includes water, soil, biota.
N₂ (78%), O₂ (21%), Ar, CO₂, H₂O vapor.
Primary: directly emitted (SO₂, CO). Secondary: formed from reactions (O₃, smog).
Trapping of heat by GHGs (CO₂, CH₄) → warms Earth.
Rise in avg. temp → melting ice, sea level rise, extreme weather.
Absorbs infrared radiation and re-emits it.
Absorbs outgoing IR and radiates back to surface.
Damages forests, aquatic life, erodes buildings.
Thinning of ozone layer; noticed over Antarctica (1980s).
Increased UV radiation → skin cancer, cataracts, ecosystem damage.
Stratosphere (15–35 km altitude).
H⁺ ions displace Ca²⁺, Mg²⁺, Al³⁺ becomes toxic.
Binds hemoglobin stronger than O₂ → asphyxiation.
Volcanoes, decomposition of organic matter, sea spray.
High specific heat, cohesion/adhesion, universal solvent, density anomaly.
Water rises in narrow tubes due to adhesive and cohesive forces.
Bent shape, electronegativity difference → partial charges.
Soft: lather easily; Hard: contains Ca²⁺/Mg²⁺ salts.
Adding limewater (Ca(OH)₂) precipitates CaCO₃/Mg(OH)₂.
Hard deposits of CaSO₄/Mg salts; removed by mechanical/chemical descaling.
Increase crop yield, control pests.
Cannot form H-bonds, weak van der Waals interactions.
Eutrophication, non-biodegradable surfactants.
Cholera, typhoid, dysentery.
Excess fluoride causes mottling of teeth & skeletal damage.
Extraction of metals from ores.
Mineral: natural metal compound; Ore: mineral from which metal extracted profitably.
Based on density differences (e.g., washing of tin ore).
Magnetic ores separated from gangue using magnets.
Heating ore in excess air to convert sulfide to oxide (e.g., 2ZnS+3O₂→2ZnO+2SO₂).
NaCl, NH₃, CaCO₃ (limestone), water.
Less expensive, recycles NH₃, produces pure Na₂CO₃.
Complex hydrocarbon mixture from ancient marine organisms.
Heat & pressure on organic remains over millions of years.
Crude: unrefined; Residual: left after distillation (heavy fuel oil).
Diesel: transportation; Fuel oil: industrial heating/marine.
NH₃ and CO₂ (from natural gas reforming).
2NaHCO₃ → Na₂CO₃ + CO₂ + H₂O (heating).
Complete & incomplete reaction: Complete: reactants fully consumed; incomplete: equilibrium established. Reactions often don’t go to completion because of reversibility or energy barriers.
For general reaction aA + bB ⇌ cC + dD, rate forward = k_f [A]ᵃ[B]ᵇ, rate reverse = k_r [C]ᶜ[D]ᵈ. At equilibrium: k_f [A]ᵃ[B]ᵇ = k_r [C]ᶜ[D]ᵈ ⇒ Kc = k_f/k_r = [C]ᶜ[D]ᵈ/[A]ᵃ[B]ᵇ. Importance: predicts yield, direction, and effect of conditions.
Arrhenius limited to water. Lewis more general: BF₃ (acid) + NH₃ (base) → adduct. Limitations of Arrhenius: NH₃ gas + HCl gas reaction can’t be explained.
Acyclic, alicyclic, aromatic, heterocyclic. Homologous series: same functional group, gradation in properties (e.g., alkanes: CH₄, C₂H₆).
Vitamin A deficiency: night blindness. Vitamin D: rickets. Vitamin C: scurvy. B12: anemia. Sources: fruits, vegetables, dairy.
Solvay: CO₂ + NH₃ + NaCl + H₂O → NaHCO₃ ↓ → Na₂CO₃. Urea: CO₂ + 2NH₃ → NH₂COONH₄ → (NH₂)₂CO + H₂O. Urea importance: high N fertilizer (46%).
CO₂, CH₄ trap IR; acid rain: SO₂ + H₂O → H₂SO₃, oxidized to H₂SO₄. Effects: forest dieback, corrosion.
Temporary hardness (Ca(HCO₃)₂): removed by boiling or Clark’s method (Ca(OH)₂). Permanent hardness (CaCl₂, MgSO₄): removed by ion-exchange or washing soda (Na₂CO₃). Disadvantages of hard water: soap wastage, boiler scales, poor lather.
Alkanes: hydrogenation of alkenes, decarboxylation, Kolbe electrolysis. Alkenes: dehydration of alcohols, cracking of alkanes.
CFCs release chlorine radicals → O₃ destruction. Prevention: Montreal Protocol banning CFCs.
Complete & incomplete reaction: Complete reaction goes to maximum conversion; incomplete reaches equilibrium. Reactions do not go to completion due to reverse reaction, thermodynamic reversibility or activation energy barriers.
Macroscopic characteristics of forward, reverse & dynamic equilibrium: Forward: reactants decrease. Reverse: products decrease. Dynamic equilibrium: no net change, rates equal, system appears static but active at molecular level.
Physical properties of acids & bases: Acids taste sour, turn blue litmus red, react with metals. Bases taste bitter, slippery, turn red litmus blue.
Chemical properties of acids: React with bases, carbonates, metals to produce H₂, and with metal oxides.
Homologous series characteristics: Same general formula, similar chemical properties, gradation in physical properties, difference of -CH₂-.
Structural formula, condensed, electronic formula: Structural shows bonds; condensed (CH₃CH₂OH); electronic uses dots/crosses for valence electrons.
Sources of proteins & lipids: Meat, beans, eggs, dairy (proteins); oils, butter, nuts (lipids). Functions: enzymes, hormones, energy storage.
Concentration of ore processes: Hydraulic washing, magnetic separation, froth flotation, leaching.
Extraction of copper: Roasting of chalcopyrite → smelting → Bessemerization → electrolytic refining.
Urea status: Most used nitrogenous fertilizer, crucial for global food security.
Water as universal solvent: Due to polarity & hydrogen bonding, dissolves many ionic & polar substances.
Water pollution effects: Eutrophication, bioaccumulation of toxins, waterborne diseases like cholera. Prevention: proper sanitation, wastewater treatment.
Total comprehensive coverage from Units 9–16 with over 3000 words, including definitions, long answer summaries, and equilibrium derivations.