Language of Chemistry

Introduction: The universe is composed of matter and energy. Matter and energy are inter-convertible to each other. The branch of modern science which deals with the study of composition, transformation and properties of the matter is known as chemistry. Chemistry can be classified as physical chemistry, inorganic chemistry and organic chemistry.

Element: An element is defined as a pure substance which can neither be decomposed into nor built from simpler substance by any kind of physical or chemical methods. Example: Hydrogen, Oxygen, Carbon, Sodium, etc. the concept of elements was first introduced by Robert Boyle.

Atom: The smallest particle of an element which can take part in chemical changes is called an atom. It may or may not be capable of independent existence.

Compound: A compound is a substance produced by union of two or more element in a definite proportion. It can be decomposed into two or more simple substance. Eg.

Water- H₂O

Glucose-C₆H₁₂O₆

Ammonia-NH₃ etc.

Molecule: A  molecule is defined as the smallest unit (particle) of any kind of substance, elements or compound which can exist independently and can possess all properties of substance. Eg.H₂,O₂,O₃, P₄, S₈, H₂O, CH₄, PCl₅, etc.

Homonuclear Molecule: Molecule formed by the combination of similar kind of atoms are called homonuclear molecule eg. O₂,O₃, P₄, S₈etc.

Heteronuclear Molecule: Molecule formed by the combination of different kind of the atoms of different elements are called heteronuclear molecule. Example: H₂O, CH₄, PCl₅,, etc.

Symbol: Symbol is defined as the abbreviation or shorthand sign for the full name of an element. One or more letters is used to write the symbol of an element.

Examples:

Hydrogen-H, Oxygen-O, Magnesium-Mg, Calcium-Ca etc.

Valency: Valency of an element is the combining capacity of the element which is measured in terms of hydrogen atoms or its equivalent which combine with one atom of that elements.

Examples:

H=1, O=2, N=3, Al=3, Ca=2, Na=1, etc.

Certain element can have more than one valency that is they exhibit variable valency. Example Fe - 2 and 3, Cu - 1 and 2, Sn - 2 and 4 etc

Radical: A radical may be defined as an atom or group of atoms having positive or negative charge and behaves as a single unit in chemical change.

Eg. Cl¯, Na⁺, OH¯, Ca⁺⁺, Al⁺⁺⁺, SO₄¯¯, etc.

(i)  Acid Radical :- All electronegative charge particles except OH¯ and O¯¯ are called acid radical. Eg. Cl¯, SO₄¯¯,NO₃¯, PO₄¯ etc. They are derived from acid.

(ii) Basic Radical :- All electropositive charge particles except H⁺ are called acid radical. They are derived from base. Eg. Na⁺,Ca⁺⁺,K⁺, Mg⁺⁺,NH₄⁺ etc.

List of some common Radicals :-

	Monovalent	Radical	4	Sulphate	SO4
1.	Amide	NH2	5	Thiosulphate	S2O3
2.	Bisulphate	HSO4	6	Tetrathionate	S4O6
3.	Bicarbonate	HCO3	7	Pyrosulphate	S2O7
4.	Meta borate	BO2	8	Persulphate	S2O8
5.	Formate	HCOO	9	Dichromate	Cr2O7
6.	Acetate	CH3COO	10	Tetraborate	B4O7
7.	Meta phosphate	PO3	11	Zincate	ZnO2
8.	Perchlorate	ClO4	12	Stannite	SnO2
9.	Chlorate	ClO3	13	Stannate	SnO3
10.	Chlorite	ClO2	14	Manganate	MnO4
11.	Thiocyanate	CNS	15	Chromate	CrO4
12.	Cyanate	CNO	16	Plumbite	PbO2
13.	Cyanide	CN		Trivalent	Radical
14.	Hydroxide	OH	1	Aluminate	AlO3
15.	Hypochlorite	ClO	2	Phosphate	PO4
16.	Permanganate	MnO4	3	Arsenite	AsO3
	Divalent	Radical	4	Arsenate	AsO4
1.	Carbonate	CO3	5	Stibnate	SbO4
2.	Oxalate	C2O4	6	Stibnite	SbO3
3.	Sulphite	SO3	7	Ferricyanide	Fe(CN)6

Common Name: Some Compound have common name use in every day life. Some common names are listed below:

1.	Aqua fortis	HN03	15.	Milk of lime	Ca(OH)2
2.	Aquaregia	Conc. HNO3+Conc.3HCl	16.	Oil of vitriol	H2SO4
3.	Antacid	Mg(OH)2.Al(OH)3	17.	Red lead	Pb3O4
4.	Baking soda	NaHCO3	18.	Sal ammoniac	NH4Cl
5.	Bleaching powder	CaOCl2	19.	Washing soda	Na2CO3.10H2O
6.	Black oxide of iron	Fe304	20.	Tear gas (Chloropicrin)	CCl3NO2
7.	Potassium ferricyanide	K3Fe(CN)6	21.	Potassium ferrocyanide	K4Fe(CN)6
8.	Epsom salt	MgSO4.7H2O	22.	Condy’s Crystal	KMnO4
9.	Glauber’s salt	Na2SO4.10H2O	23.	White vitriol	ZnSO4.7H2O
10.	Green vitriol	FeSO4.7H2O	24.	Gypsum	CaSO42H2O
11.	Hypo	Na2S2O3.5H2O	25.	Caustic soda	NaOH
12.	King of chemicals	H2SO4	26.	Lithrage	PbO
13.	Load stone	Fe3O4	27.	Vinegar	CH3COOH
14.	Laughing gas	N2O	28.	Lunar Caustic	AgNO3

Dalton’s Atomic Theory : ( In 1808, John Dalton )

Postulate :

1. All matter consists of extremly small individual particles called atoms.

2. Atoms of same element are all alike.

3. Atoms of different elements are entirely different and have different properties.

4. Atoms can not be destroyed created or transformed into atoms of other elements.

5. Atoms combines together in simple whole number ratio to give compounds.

6. The relative number and kinds of atoms are constant in a given compound.

Stoichimetry :-

Stoichimmetry is the branch of chemistry which deals with the weight relationship in chemical rxⁿ and weight relationship that prevails in a chemical compound.

Law of Chemical Combination.

1. The Law of Conservation of mass: Mass neither be created nor be destroyed during chemical reaction or total mass of reactant is equal to total mass of product formed in chemical reaction.

2. The Law of definite proportions: The same chemical compound always contains the same elements combined together in definite proportion by weight regardless of the origin or mode of formation of compound.

3. The Law of multiple proportions: When one elements combine with another element to form two or more different compounds, then the weight of one of the element which combine with the constant weight of the other bear a simple whole number ratio to one another.

4. Law of reciprocal or equivalent proportions: When two different elements combine separately with the same weight of the third element the ratio in which they do so will be the same or simple multiple of the ratio in which they unite with each other.

5. Law of gaseous volumes: Whenever gases react they do so in volumes which bear a simple ratio to one another and to the volumes of the products if these are also gases provided all measurements are made under similar condition to temp^r & pressure.