1. Chemistry
Element:Itcannotbe splitintosimplersubstances,e.g.,iron,sulphur,oxygen,gold.There are about106
elements.
Compound:Itcan be splitintosimplersubstancesandisformedbythe unionof twoor more elements
indefinite proportions byweight,e.g.
1. Water can be splitintohydrogenandoxygen.
2. Iron sulphide issplitintoironandsulphur.
3. Chalkis made of calcium,carbon and oxygen.
4. Carbondixoide ismade upof carbonand oxygen.
2. Mixture:Itis one inwhichtwo or more substancesare mixedtogetherinanyratiowithoutalteringtheir
properties.
1. Sand and salt
2. Sugar andwater
3. Air isa mixture of nitrogenandoxygen
4. Gun-powderisamixture of nitre,charcoal andsulphur
3. Hard and SoftWater: Hard wateris that waterwhichdoesnotproduce latherwithsoapeasily.Soft
waterproduceslatherwithsoapveryeasily.
There istwo kindsof hardness: -
(i) Temporary
(ii) Permanent.
Temporaryisdue to bicarbonatesof calciumandmagnesium.Canbe removedby
(i) boiling,(ii) additionof lime.
Permanentisdue tothe sulphatesandchloridesof calciumandmagnesium.
Permanenthardnesscanbe removedby(I) additionof washingsoda,or(ii) by
distillation.
Alloy:Isa mixture of twoor more metalsina certainproportion.Alloysare made toimpart
certainspecial propertiestothe metalsinquestion.Forexample,stainlesssteelismade
usingIron,Manganese,Carbonetc.to give ithighstrength,elasticity etcwhichisnotfound
inIron.
Amalgam:anyalloycontainingMercuryas an essential componentisknownasamalgam.
Chemical Namesof substances:
Chemical Name of the Substance
Substance Chemical Name Composition
Greenvitriol Iron sulphate Iron,sulphurandoxygen
Litharge Lead monoxide Lead andoxygen
White vitriol Zincsulphate Zincsulphurand oxygen
Causticlotion Silvernitrate Silver,nitrogenandoxygen
Candyfluid Potassiumpermanganate Potassium, manganeseandoxygen
Blue vitriol Coppersulphate Copper,sulphurandoxygen
Kansi (Alloy) Bronze Copper,zinc,tin
Pital (Alloy) Brass Copper,zinc
4. Chemical Name of the Substance
Shora or nitre Potassiumnitrate Potassium, nitrogenandoxygen
Causticpotash Potassiumhydroxide Potassium, hydrogenandoxygen
Chile saltpeter Sodiumnitrate Sodium, nitrogenandoxygen
Bakingsoda Sodiumbicarbonate Sodium, hydrogen,carbonandoxygen
Washingsoda Sodiumcarbonate Sodium, carbonand oxygen
Commonsalt Sodiumchloride Sodiumandchlorine
Causticsoda Sodiumhydroxide Sodium, hydrogenandoxygen
Gluber’ssalt Sodiumsulphate Sodium, sulphurandoxygen
5. Chemical Name of the Substance
Iron pyrites Iron sulphide Iron and sulphur
Galena Lead sulphide Lead andsulphur
Gyspum Calciumsulphate Calcium, sulphurandoxygen
Epsom Magnesiumsulphate Magnesium, sulphurandoxygen
Aspirin Acetyl SalicylicAcid
Vinegar AceticAcid(Glacial) Carbon,Hydrogen,Oxygen
BleachingPowder CalciumOxychloride Calcium, Oxygen,Chlorine
Marble CalciumCarbonate Calcium, Carbon,Oxygen
Rust FerricHydroxide Iron,Hydrogen,Oxygen
Plasterof Paris
HydratedCalcium
Sulphate Calcium, Sulphur,Hydrogen,Oxygen
