1. Matter

• Antoine Lavoisier — Father of (Modern) Chemistry.
• Kanad (Kaṇāda) — all matter made of extremely small particles: atoms.
• Three physical states: Solid, Liquid, Gas.
• Fourth state: Plasma; Fifth state: Bose–Einstein Condensate.
• Changing temperature / pressure → state changes.
• Exceptions: Wood, stone — only solid state.
• Water — exists in all three physical states.

Effect of Pressure on Melting Point

1. Volume increases on melting → Melting point ↑ with pressure (e.g., wax, naphthalene).
2. Volume decreases on melting → Melting point ↓ with pressure (e.g., ice, cast iron).

Volume Change on Melting / Freezing

• Some crystalline substances: volume increases on freezing → solid sinks in own liquid.
• Ice, cast iron, antimony, bismuth — contract on melting → solid floats in own liquid (ice floats in water).
• Printing metals — expand on solidifying.
• Silver/Gold coins — not cast; made by hammer striking.
• Alloys — lower melting point than constituents (impurity effect).
• Pressure ↑ → boiling point ↑; pressure ↓ → boiling point ↓.

Major Elements in Earth’s Crust

• Oxygen 46.60%, Silicon 27.72%, Aluminium 8.13%, Iron 5%, Calcium 3.6%, Sodium 2.83%, Potassium 2.59%, Magnesium 2.09%, Hydrogen 0.14%.

Average Element Composition (Human Body)

• Oxygen 65%, Carbon 18%, Hydrogen 10%, Nitrogen 3%, Calcium 2%, Phosphorus 1%, Potassium 0.35%, Sulphur 0.25%, Sodium & Chlorine 0.15%.

Major Atmospheric Gases

• Nitrogen 78%, Oxygen 21%, Argon 0.93%, Carbon dioxide 0.04%.

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2. Atomic Structure

• 20th century scientists – J. J. Thomson, Rutherford, Chadwick proved atom divisible.
• Atom contains 3 fundamental particles: Proton, Electron, Neutron.
• Other subatomic particles: Positron, Neutrino, Antineutrino, Meson.
• Same type of atoms found in elements.

Fundamental Particles

• Electron – Charge –1, Mass 9.109×10⁻²⁸ g, 0.000548 amu, discovered by Thomson.
• Proton – Charge +1, Mass 1.672×10⁻²⁴ g, 1.007 amu, discovered by Goldstein.
• Neutron – Charge 0, Mass 1.674×10⁻²⁴ g, 1.008 amu, discovered by Chadwick.

Nucleus

• Discovered by Rutherford (1911).
• Composed of Protons + Neutrons = Nucleons.
• Positive charge present.
• Electrons revolve around nucleus in orbits.
• Number of electrons = protons → atom is electrically neutral.
• Filling order of electrons → Aufbau Principle: lowest energy orbital filled first.

Atomic Number (Z)

• Defined as number of protons in nucleus.
• Example: Hydrogen (Z = 1) → nucleus contains 1 proton, 0 neutron.

Mass Number (A)

• A = Z + N (Protons + Neutrons).
• Represents total number of nucleons.

Isotopes

• Same Z, different A.
• Example: ¹H¹, ¹H², ¹H³.
• Hydrogen isotopes – Protium (0 neutron), Deuterium (1 neutron), Tritium (2 neutrons).
• Most isotopes → Polonium.

Isobars

• Same A, different Z.
• Example: ¹⁸Ar⁴⁰, ¹⁹K⁴⁰, ²⁰Ca⁴⁰.

Isotones

• Same number of neutrons.
• Example: ¹H³, ²He⁴ → both have 2 neutrons.

Isoelectronic Species

• Same number of electrons.
• Example: Na⁺, Mg²⁺, F⁻, O²⁻ → all have 10 electrons.

Radioactivity

• Property of atomic nucleus.
• Discovered by Becquerel.
• Measured by Geiger Counter.
• Elements with Z > 83 are radioactive.
• Radium most radioactive; discovered by Marie Curie (1902).
• Emissions: α (positive charge), β (negative charge), γ (neutral electromagnetic ray).
• Penetration power: γ > β > α.
• Radioactive disintegration – nuclear, not chemical process.

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Periodic Table

• Mendeleev’s law – properties are periodic function of atomic mass.
• Mendeleev’s table – 9 groups, 7 periods.
• Modern periodic law (Moseley, 1913) – properties are periodic function of atomic number.
• Modern table – 7 periods, 18 groups.
• Lanthanides – Z = 57–71; Actinides – Z = 89–103.
• Fluorine – highest electronegativity.
• Noble gases – lowest melting points.

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Chapter 3 – Classification of Elements

• According to Mendeleev’s periodic law, physical and chemical properties of elements are periodic function of atomic mass.
• Mendeleev’s periodic table – 9 groups (columns), 7 periods (rows).
• Modern periodic law (Moseley, 1913) – properties of elements are periodic function of atomic number.
• Modern periodic table – 7 periods, 18 groups.
• Lanthanide series – atomic number 57–71.
• Actinide series – atomic number 89–103.
• Fluorine – highest electronegativity.
• Noble gases – lowest melting points.
• Chlorine – highest electron affinity.

Main Trends in Modern Periodic Table

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Chapter 4 – Chemical and Physical Changes

1. Physical Change

• No new substance formed.
• Reversible.
• Examples: Melting of ice, Evaporation of water, Boiling of water, Condensation of steam, Bulb glowing, Breaking of glass, Dissolving sugar in water.

2. Chemical Change

• New substances formed.
• Irreversible.
• Examples: Burning of magnesium ribbon, Burning of paper, Rusting of iron, Milk turning into curd, Cooking of food.

Corrosion

• Silver – black coating.
• Copper – green coating.
• Iron – brown coating (rust).

Solution

• Transparent and homogeneous mixture.
• Solvent – present in larger amount.
• Solute – present in smaller amount.

Effect of Temperature on Solubility

• Solubility of most solids increases with temperature.
• Some solids’ solubility decreases with temperature (e.g., Na₂SO₄, Ca(OH)₂, Ca(NO₃)₂).
• Solubility of gases decreases with increase in temperature.

Effect of Pressure on Solubility

• Solubility of gases increases with pressure.

Dispersion

• Process when particles of one substance scatter over another substance.

Suspension

• Particle size: 10⁻³ – 10⁻⁴ cm.
• Visible to naked eye.
• Examples: Muddy water of river, Smoke in air.

Colloid

• Particle size: 10⁻⁵ – 10⁻⁷ cm.
• Not visible to naked eye.
• Examples: Milk, Gum, Blood, Ink.

Types of Colloids

1. Sol – solid in liquid (e.g., rubber gloves).
2. Gel – solid dispersed in liquid (e.g., jelly, gelatin).
3. Aerosol –
   • Liquid in gas (e.g., fog, clouds, ammonia solution in air).
   • Solid in gas (e.g., smoke, iodine solution in air).
4. Emulsion – liquid in liquid.
   • Natural example: Milk.
   • Artificial examples: Paint, Soap, Detergents.

• Colloids separated from true solutions by Dialysis.

Important Facts

• Alloys → solution of solid in solid.
• Electrolysis of water → energy released as heat.
• Pasteurization (by Louis Pasteur) – milk heated at 145–150°F for 30 min, then cooled suddenly. Prevents spoilage.
• Presence of impurities → raises boiling point, lowers melting point.
• Chromatography – used to separate components of mixture.
• Some solids change directly solid ↔ vapor (e.g., Camphor, Naphthalene, NH₄Cl) → Sublimation.

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Chapter 5 – Inorganic Chemistry

5A.1 Metals, Minerals and Ores

• Less reactive metals (Gold, Platinum) → found in free state.

• In Earth’s crust: Aluminium (7%) > Iron (4%) > Calcium (3%).

• Most reactive metal – Potassium (K).

• Reactivity order – K > Na > Ba > Ca > Mg > Al > Zn > Fe > Cu.

• Lithium (Li) – lightest metal.

• Osmium (Os) – heaviest metal.

• Platinum – hardest metal.

• Diamond – hardest element.

• Uranium (U) – heaviest natural element; India’s largest producer – Jharkhand.

• Marble → Calcium carbonate (CaCO₃).

• Ruby, Sapphire → Aluminium hydroxide minerals (AlOH).

• Fluorescent lamp → Mercury vapor + Argon gas.

• Pure gold – 24 carat; ornaments – 10–22 carat.

• Limestone – Calcium carbonate (CaCO₃).

• Fireworks colors – Green → Barium (Ba), Red → Strontium (Sr).

• Tungsten (W) – Rajasthan (Degana mine).

• Plaster of Paris (CaSO₄·½H₂O) – Calcium sulphate; used by doctors, artists, sculptors.

• Mica (Abhrak) – conductor of heat, insulator of electricity.

• Mercury (Hg) – best conductor of heat among liquids; liquid at room temperature.

• Gallium (Ga) – liquid near room temperature.

• Lead (Pb), Copper (Cu), Silver (Ag), Gold (Au), Platinum (Pt) – do not react with water or steam.

• Wrought iron – least carbon → purest form of iron.

• Siderosis – lung disease due to inhalation of iron dust.

• Silver chloride (AgCl) – Horn silver.

Important Minerals and Ores

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5A.2 Alloys

• Brass = Cu + Zn → utensils, decorative items.
• Steel = Fe + C → vehicles, buildings, tools.
• Stainless steel = Fe + Cr + Mn + C → utensils, sports goods, daily-use items.
• Solder = Pb + Sn → electrical fuses.
• Bronze = Cu + Sn → idols, statues.
• Duralumin = Al + Cu + Mg + Mn → aircraft, kitchen items.
• German silver = Cu + Ni + Zn → utensils, other items.
• Nichrome = Ni + Cr + Fe → heating coils.

Important Facts

• Galvanization – zinc coating on iron to prevent rusting.
• Anodizing – coating of Al₂O₃ on aluminium to prevent rusting.
• Aluminium – used in ship building, railway coaches.
• Amalgam – alloy of mercury with metals (except iron).

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5A.3 Acids, Bases and Salts

Acids

• Compound that accepts lone pair of electrons, donates proton, or produces H⁺ ions in water.
• Properties: sour taste, turns blue litmus red.

Uses:

• Hydrochloric acid – digestion.
• Nitric acid (HNO₃) – purification of gold, silver.
• Sulphuric acid (H₂SO₄) + Nitric acid – cleaning iron before zinc coating.
• Oxalic acid – removes rust stains from cloth.

Natural acids:

• Acetic acid – vinegar.
• Citric acid – lemon, orange.
• Tartaric acid – tamarind, grapes.
• Oxalic acid – tomato.
• Lactic acid – curd, sour milk.
• Methanoic acid – ant sting, bee sting.

Aqua Regia – mixture of conc. HCl + conc. HNO₃ (3:1) → dissolves gold, platinum.

Strength order – HCl > HNO₃ > H₂SO₄ > CH₃COOH.

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Bases

• Compound that donates lone pair, accepts proton, or reacts with acid to give salt + water.
• Properties: bitter taste, turns red litmus blue.

Examples:

• KOH, NaOH – soluble bases (alkalis).
• ZnO, Cu(OH)₂, FeO, Fe₂O₃ – insoluble bases.

Uses:

• Ca(OH)₂ (slaked lime) – whitewash, plaster, bleaching powder, softening water, neutralizing acid burns.
• NaOH (caustic soda) – soap, paper, cleaning factories, petroleum refining.
• Mg(OH)₂ (milk of magnesia) – antacid.

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Salts

• Formed when acid reacts with base → salt + water.

Important salts:

• NaCl – common salt, used in food, pickles.
• NaHCO₃ – baking soda, relieves acidity.
• Na₂CO₃ – washing soda, used for clothes.
• NaOH – used in detergents.

pH scale – measures acidity/alkalinity:

• pH < 7 → acidic.
• pH > 7 → basic.
• Human blood pH → 7.4; normal range 7–7.8.

Other Important Facts

• Tooth enamel → calcium phosphate, hardest body substance.
• Breath analyzer – works on acid-base reaction.
• Earth’s crust composition (by mass): Oxygen 46.8% > Silicon 27.72% > Calcium 3.65% > Carbon 0.6%.
• Most abundant element in universe → Hydrogen.
• Sulphuric acid (H₂SO₄) → king of chemicals.
• Iodized salt → potassium iodide + sodium iodide.

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Important salts with formulas:

• Blue vitriol – CuSO₄·5H₂O.
• Green vitriol – FeSO₄.
• White vitriol – MgSO₄·7H₂O.
• Hypo – Na₂S₂O₃·5H₂O.
• Bleaching powder – Ca(OCl)Cl.
• Epsom salt – MgSO₄.
• Baking soda – NaHCO₃.
• Washing soda – Na₂CO₃.

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Important Compounds

Facts

• Sodium chloride (NaCl) is the most abundant salt in oceans, used as an essential food component.
• Table salt is formed by combining strong base (Na⁺) and strong acid (Cl⁻).
• Bleaching powder is an oxidizing agent, dissolves in water, but due to impurities cannot produce pure chlorine.
• Sodium thiosulfate is used in photography and as antichlor.
• Photographic plates are coated with silver bromide.

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5B. Nonmetals

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5B.1 Carbon and Its Allotropes

• Carbon dioxide is an inorganic compound made of carbon and oxygen.
• Carbon dioxide is not an allotrope of carbon.
• Carbon forms maximum compounds.
• Carbon allotropes are graphite, diamond, graphene, buckminster fullerene (C₆₀).
• Diamond is hardest, graphite is soft.
• Graphite used in making pencil lead.
• Graphite acts as lubricant in heavy machines.
• Diamond used in cutting glass and engraving designs.
• Fullerene (C₆₀) has 60 carbon atoms.
• C₆₀ structure has 20 hexagons and 12 pentagons.
• Graphene is two-dimensional, with excellent electrical conductivity.
• Graphene is very thin yet strongest known material.
• Graphene density is so high that even helium atoms cannot pass through.
• Graphene used in computer chips, communication devices, touchscreens.
• Hydrochloric acid reacts with soluble silicates to form insoluble silica.
• Hydrochloric acid used in etching glass.
• Solid CO₂ is called dry ice or snow ice.
• Dry ice used in making ice cream and as refrigerant.

Carbon Content in Coal Types

• Bituminous is medium quality, anthracite is best quality coal.
• Cast iron has high carbon content (3.5–4.5%).
• Wrought iron has low carbon content (0.04–0.08%).
• Diamond, glass, sand, quartz, graphite exist as crystal forms of carbon.
• Calcium sulfate makes water hard and unsuitable for use.

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5B.2 Hydrogen and Its Compounds

• Hydrogen has atomic number 1, shows properties of alkali metals and halogens.

• Hydrogen isotopes are:

  1. Protium – H / ¹H
  2. Deuterium – D / ²H
  3. Tritium – T / ³H

• Deuterium oxide (D₂O) is called heavy water.

• Heavy water discovered by Urey.

• Heavy water used in nuclear reactors as moderator.

• Heavy water harmful for living beings.

• Hard water does not lather with soap, contains calcium and magnesium salts.

• Hardness caused by chlorides, sulfates, bicarbonates of Ca and Mg.

• Hydrogen peroxide (H₂O₂) is pale blue liquid.

• H₂O₂ used as antiseptic and bleaching agent.

• Water gas = CO + H₂.

• Producer gas = CO + N₂.

• Drinking water must be free from bacteria.

• Water purification methods: bleaching powder, reverse osmosis, coagulation, sedimentation.

• Hydrogenation process converts oils into ghee.

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5B.3 Sulphur, Nitrogen, Halogens and Inert Gases

• Helium (He) + Oxygen mixture used by divers for breathing in deep seas.
• Sulphur hexafluoride (SF₆) is colorless, odorless, non-flammable inorganic compound.
• Sulphur hexafluoride is highly non-reactive.
• Nitrous oxide (N₂O) is called laughing gas, used as anesthetic.
• Xenon (Xe) is called stranger gas, found in very small amount in atmosphere.
• Nitrogen gas used in airplane tires to reduce risk of explosion.
• Nitrogen is essential for plant growth.
• Leguminous plants increase nitrogen content in soil.
• Deficiency of nitrogen in plants causes poor growth.
• Tear gas contains chloroacetophenone, acrolein, etc.
• Ammonia (NH₃) in tear gas causes irritation in eyes.
• Halogen gases are chlorine, fluorine, bromine, iodine.
• Iodine remains solid at normal temperature.
• Halogens are highly reactive nonmetals.
• Fluorine is the most reactive element.
• Bromine compounds are used as painkillers.
• Inert gases – He, Ne, Ar, Kr, Xe, Rn.
• Inert gases are also called noble gases or rare gases.

Important Facts

• Carbon dioxide (CO₂) in atmosphere = 0.03%, Argon = 0.93%, Oxygen = 20.95%.
• Nitrogen (N₂) is the most abundant gas in atmosphere (78%).
• Gaseous cycle main reservoirs are atmosphere and oceans.
• Gaseous cycles include carbon cycle, oxygen cycle, nitrogen cycle, water cycle.
• Gases containing hydrogen form hydrogen bonds with water, hence are more soluble.
  • Example: Ammonia (NH₃).
• Helium gas used in balloons, as it does not form explosive mixture with air.
• Tubelight contains low pressure neon and mercury vapors.

6. Organic Chemistry

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6.A Hydrocarbons

1. Hydrocarbons are compounds of carbon and hydrogen.
2. All organic substances are made of carbon compounds in which carbon is essential.
3. Carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur are basic elements.
4. Hydrocarbons are obtained from coal and petroleum, main sources of energy.
5. LPG and CNG are domestic fuels and vehicle fuels derived from petroleum.
6. Saturated hydrocarbons have single bonds (C–C, C–H).
7. Alkanes are saturated hydrocarbons.

Important Alkanes

1. Methane found in marshes.
2. Ink used in printing is made from methane.
3. Rice fields, coal mines, cattle release methane.
4. Wetlands and oceans are natural methane sources.
5. Butane used in cigarette lighters.
6. Bhopal Gas Tragedy (3 Dec 1984) due to methyl isocyanate leak.
7. Alkanes usually unreactive towards acids, bases, oxidizing and reducing agents.

Unsaturated Hydrocarbons
15. Unsaturated hydrocarbons have double or triple bonds.
16. Alkenes and alkynes are unsaturated.
17. Ethylene is colorless, slightly sweet-smelling, sparingly soluble in water.

Uses of Ethylene

1. As anesthetic

2. For ripening fruits

3. For making polyethylene

4. For making mustard gas

5. Mustard gas used in chemical warfare.

6. World War I saw use of mustard gas.

7. Acetylene is colorless, odorless, slightly soluble in water.

8. Compressed acetylene is highly explosive.

9. Acetylene + oxygen used in welding and metal cutting.

10. Acetylene used for artificial fruit ripening.

11. Calcium carbide also used for ripening fruits.

12. Pyrene used in fire extinguishers.

13. Neon used in lighting.

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6.B Alcohols

1. Methanol (wood spirit) obtained from wood distillation.
2. Methanol found in oils of wintergreen and other plants.
3. Methanol is poisonous, causes blindness and insanity.

Uses of Methanol
a. As solvent in paints, varnishes.
b. As fuel additive with petrol in motor engines.
c. In dyes, perfumes, medicines manufacturing.
d. Methanol + water mixture used in automobile radiators as antifreeze.

Alcohol Types

1. Ethanol commonly called alcohol.
2. Ethanol is the main ingredient of liquors.
3. Ethanol also called spirit of wine.
4. Ethanol mixed with methanol and pyridine becomes poisonous (denatured alcohol).
5. Fermentation of sugar produces ethanol.
6. Molasses is the cheapest raw material for alcohol production.

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6.C Polymers

Important Polymers

1. Teflon surface is slippery, used in cooking utensils coating.
2. Teflon also used as insulator.
3. Teflon chemical name Polytetra flouro Ethylene.
4. PVC used in pipes, records, bags, waterproof items.
5. Neoprene used in synthetic rubber.
6. Resin, wool, starch, protein, cotton, leather are natural polymers.
7. Kevlar (polyamide) used in bulletproof vests.
8. Polycarbonate used in bulletproof glass.
9. Zinc oxide used for brightening.
10. Bakelite made from phenol + formaldehyde.

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6.D Organic Acids

1. Lactic acid causes muscle fatigue.
2. Tartaric acid used in baking powder.
3. Oxalic acid used in photography.

Important Acids and Sources

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6.E Explosives

1. TNT – Trinitrotoluene
2. TNG – Trinitroglycerin (Nobel oil, used in dynamite)
3. TNP – Trinitrophenol (picric acid)
4. Amatol – mixture of TNT and ammonium nitrate
5. Dynamite – invented by Alfred Nobel in 1860s
6. RDX – Cyclonite (Chemical name), discovered by George Friedrich Henning (Germany)
7. Nitroglycerin – essential explosive component

• Mines contain gases like CO, CO₂, methane, O₂, N₂, H₂.
• Methane-air mixture causes mine explosions.
• Nitrous oxide used as anesthetic, not explosive.

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6.F Fuels

1. Incomplete combustion of wood, coal, petrol produces carbon monoxide.
2. Coal burning indoors dangerous due to CO poisoning.
3. Coal and diesel combustion releases SO₂.
4. SO₂ is suffocating and corrosive.
5. Petrol combustion releases nitrogen oxides.
6. SO₂ + NOₓ dissolved in water form acid rain.
7. Excessive fuel burning releases CO₂ into atmosphere.
8. CO₂ is main cause of global warming.
9. Coal, petroleum, natural gas are fossil fuels.
10. Coke, coal tar, coal gas obtained from coal.
11. Petroleum also called mineral oil or crude oil.
12. Petroleum and natural gas found in seabeds.
13. Natural gas is mixture of hydrocarbons and other gases.
14. Natural gas contains mainly methane.
15. Hydrogen has highest calorific value.
16. Octane number denotes petrol quality.

Other Important Facts

• Hydrogen has the highest fuel value or calorific value.
• Octane number shows petrol quality and cetane number shows diesel quality.
• Diesel engines use fuel of diesel vapor and air.
• Biogas or gobar gas used domestically contains methane and carbon dioxide.
• Biogas is produced by anaerobic decomposition.
• LPG main components are ethane, propane, butane.
• LPG mainly contains propane, butane, isobutane under high pressure.
• LPG leakage is detected by adding strong-smelling substance like mercaptan.
• CNG main component is methane.
• Tetraethyl lead is added to petrol to prevent engine knocking.
• Tetraethyl lead increases anti-knock rating of petrol.
• Diesel is used in heavy vehicles due to high efficiency and economy.

Important Gases and Their Components

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7. Food Preservation, Nutrition and Medicines

1. Enzymes cause spoilage of food.
2. Microorganisms produce enzymes in food.
3. Boiling milk kills microorganisms.
4. Low temperature or freezing slows microorganism activity and preserves food.
5. Sodium benzoate and benzoic acid prevent growth of bacteria and yeast, hence called food preservatives.

Medicines

1. Antipyretics – used to reduce fever. Examples: Aspirin, Paracetamol, Phenacetin.
2. Analgesics – reduce pain without unconsciousness or nervous depression. Examples: Aspirin, Paracetamol, Morphine, Cocaine, Heroin.
3. Antiseptics – kill microorganisms and stop their growth. Examples: Mercuric chloride, Boric acid, Iodoform, Potassium permanganate.
4. Disinfectants – kill microorganisms rapidly. Examples: Phenol, Cresol, Methyl phenol, Hydrogen peroxide, Chlorine, Bleaching powder, Sulphur dioxide.
5. Tranquilizers – reduce mental stress and depression. Examples: Rauwolfia serpentina, Luminal, Seconal.
6. Antibiotics – chemical substances obtained from microorganisms that kill microbes. First penicillin discovered by Alexander Fleming in 1929.
7. Food preservatives – protect food from spoilage by bacteria, yeast, fungi. Examples: Sodium benzoate, Sodium metabisulfite, Sorbic acid, Ethylene oxide, Propylene oxide.

Other Important Facts

• Animal charcoal used for decolorizing raw sugar.
• Honey contains fructose as main component.
• Aspirin is an antipyretic and analgesic, obtained from tree latex.
• Potassium bromide (KBr) is a salt used as sedative medicine.
• Carbon monoxide (CO) reacts with hemoglobin to form carboxyhemoglobin, causing thick blood and stopping circulation, leading to death.
• Milk is an emulsion containing vitamin C and other nutrients.
• Milk souring is due to lactic acid.
• Curd formation is caused by Lactobacillus bacteria.
• Lactobacillus converts milk sugar lactose into lactic acid.
• Clove oil contains eugenol, a natural analgesic and antiseptic.

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8. Detergents

1. Detergents are organic compounds with soap-like cleaning properties.
2. Soap cleans only in soft water.
3. Sodium stearate is an example of soap.
4. Vegetable oil + caustic soda/potash used in making soap.
5. Detergents work in both soft and hard water.
6. Sodium lauryl sulfate is a detergent.
7. Soap grease removed by emulsification.
8. Detergents are also purifying agents.

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9. Fertilizers

Fertilizers are classified into three categories:

1. Nitrogen fertilizers – main are ammonium nitrate and urea.
2. Phosphate fertilizers
3. Potassium fertilizers

Biofertilizers

1. Some microorganisms fix nitrogen in soil. Examples: Azotobacter, Clostridium, Rhizobium.
2. For wheat cultivation, nitrogen fertilizer is essential.

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Fertilizers (Continuation)

1. Plants absorb nitrogen in form of nitrate.
2. Humus is an example of organic colloid.
3. Green manure crops: Sunhemp, Dhaincha, Guar, Lobia, Moong, Urad, Wild Indigo.
4. Azolla, Anabaena, Nostoc, Blue-green algae increase nitrogen fixation in rice crop.
5. Rhizobium fixes nitrogen in legume crops.
6. Azotobacter fixes nitrogen in wheat crop.

Fertilizer Nutrients

• Macronutrients – N, P, K, Ca, Mg, S
• Micronutrients – B, Cl, Cu, Fe, Mn, Mo, Zn

1. Ammonium sulfate makes soil acidic.
2. Ammonium sulfate is a mixed fertilizer of ammonia and sulfur.
3. Urea (NH₂CONH₂) is an organic nitrogen fertilizer with 47% nitrogen.
4. Urea acts as nitrogenous manure.
5. Carbon dioxide is used in making urea.
6. Neem-coated urea slows nitrogen release, reduces losses, increases efficiency.

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10. Miscellaneous

1. Pyrethroid is an insecticide used in mosquito repellent medicines.
2. Quinine is a natural antimalarial drug obtained from plants.
3. Fire extinguishers use carbon dioxide, sodium bicarbonate, sulfuric acid.
4. Aluminium sulfate used for making fire-resistant cloth.
5. Potassium cyanide (KCN) used as poison to kill pests.
6. Rodenticides are chemicals to kill harmful animals like rats.
7. Carbon-14 dating used to determine age of organic substances.
8. Uranium method used to calculate Earth’s age.
9. Ozone absorbs ultraviolet radiation.
10. Zinc oxide (ZnO) is a white powder used in making paints, ointments, rubber, paper, soaps.

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Miscellaneous Facts (Continuation)

1. Cloud seeding uses silver iodide and dry ice.
2. Phosphorus pentoxide is used as a drying agent.
3. White phosphorus glows in dark and is stored under water.
4. Carbon-14 method is used to determine age of fossils.
5. Earth’s age is measured by uranium method.
6. Calcium sulfate acts as soil conditioner.
7. Ammonia causes pungent smell in urinals.
8. Fish contains foul-smelling amines.
9. Mars atmosphere contains methane.
10. Hydrochloric acid (HCl) is used in conductor batteries.
11. Manganese dioxide (MnO₂) is used in dry cells.
12. Sulphuric acid (H₂SO₄) is used in car batteries as electrolyte.

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Batteries and Chemicals

1. Nickel-cadmium is used as electrode in rechargeable batteries.
2. Ammonium chloride (NH₄Cl) and zinc chloride (ZnCl₂) act as electrolytes in dry cells.
3. Dry cell produces chemical energy into electricity.
4. Titanium is called metal of the future.
5. Cinnabar (HgS) is the ore of mercury.
6. Dry cleaning uses benzene, petrol, alcohol.
7. Eosin is a red dye, sodium chromate is also used in red dyeing.
8. Acetone is used as nail polish remover.
9. Liquid oxygen and liquid hydrogen are obtained by cryogenics.
10. Aspartame is used as artificial sweetener.
11. Brazil has made gasoline + ethanol blending compulsory.
12. Sulphuric acid (H₂SO₄) and nitric acid (HNO₃) cause acid rain.
13. Acid rain contains maximum sulphuric acid (H₂SO₄).