About Us

I am Anshul. I'm a great chemistry fan. Revathi ma'am is our chemistry teacher. We are in Class VII 'D'. I and Arjun are the authors of this blog. We are very much interested in Chemistry.
Feel free to comment on our mistakes.

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http://en.wikipedia.org/wiki/Portal:Chemistry

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Elements

Name	Latin Name	Symbol
Sodium	Natrium	Na
Magnesium	-	Mg
Aluminium	-	Al
Potassium	Kalium	K
Calcium	-	Ca
Chromium	-	Cr
Manganese	-	Mn
Iron	Ferrum	Fe
Nickel	-	Ni
Cobalt	-	Co
Copper	Cuprum	Cu
Zinc	-	Zn
Silver	Argentum	Ag
Tin	Stannum	Sn
Barium	-	Ba
Platinum	-	Pt
Gold	Aurum	Au
Lead	Plumbum	Pb
Mercury	Hydragyrum	Hg
Tungsten	Wolfram(German)	W
Vanadium	-	V
Uranium	-	U*
Thorium	-	Th*
Radium	-	Ra*

* indicates Radioactive Metals

Above is the list of common elements(metals)

But what are Elements?

Elements can be any pure substance( that is substances made with only one kind of atom) which cannot be broken into two or more pure substances by any chemical means.

List of common elements in order of decreasing reactivity

Potassium > Sodium > Calcium > Magnesium > Aluminium > Zinc > Iron > Lead > Hydrogen > Copper > Mercury > Silver > Gold

In the above list Hydrogen a non metal is included. because the metals above hydrogen donot react with water or dilute sulphuric acid or dilute hydrochloric acid and hence do not displace hydrogen.

Periodic Table

This is the list of all the elements in the world known as periodic table.

Click here for an interactive periodic table.

Properties of Metals and Non Metals

Metals

Physical Properties of metals are State, Hardness, Lustre, Density, Melting point and Boiling point, Mallebility, Ductility, Tensile Strength, Conductivity and Sonorous.

Non Metals

State, Hardness, Lustre, Density, Melting and Boiling points, Malleability, Ductility, Tensile Strength, Conductivity and sonorous.

Valency

Valency or valency number, is a measure of the number of chemical bonds formed by the atoms of a given element. Valency for some common elements and compounds.

You are going to need valency when learning how formulas were derived for acids and bases.


ELEMENTS

Element	Symbol	Valency
Hydrogen	H	+1
Oxygen	O	-2
Carbon	C	+4
Calcium	Ca	+2
Iron	Fe	+2
Aluminium	Al	+3
Sodium	Na	+1
Potassium	K	+1
Magnesium	Mg	+2
Zinc	Zn	+2
Copper	Cu	+2
Silver	Ag	+1
Lead	Pb	+2
Chloride	Cl	-1

COMPOUNDS

Compound	Symbol	Valency
Sulphate	SO4	-2
Hydroxide	OH	-1
Carbonate	CO3	-2
Nitrate	NO3	-2
Phosphate	PO4	-3
Hydrogen Carbonate	HCO3	-1

For eg. Al(OH)_{3 is the formula for Aluminium Hydroxide ( a base). Its valency is 3. So it needs 3 OHs.}

This is for people who don't understand valency

Valency is nothing but bonds for eg. it is CO₂ because C has valency+4 and O -2. So two -2s equal -4 so they cancel out forming balanced compound.

Aluminium Phosphate is AlPO₄ because Al has valency +3 and PO₄ valency -3. So they cancel directly.

Calcium Phosphate is Ca₃(PO₄)₂ because Ca's valency is +2 and PO₄'s valency is -3.So three times +2 and two times -3 make +6 and -6 respectively which cancel out.

Now Carbonate is unstable because CO₃ has 3 atoms of oxygen which makes the valency -6 but C has only +4 so it is unstable.

Easy isn't it?

BASES

Properties of Bases

• Bases are bitter to taste
• All Bases have hydroxyl ions in them
  
• Bases are soapy to touch
• All oxides are metals of Bases
• All Hydroxides of metals are bases
  

Alkalis - All bases which are soluble in water are called Alkalis

Properties of Alkalis

• All alkalis have bitter taste
• All alkali solutions have a slippery touch much like that of soap.
• We commonly say that alkalis have got a soapy touch.
• The alkalis, on coming contact with skin produce very painful blisters. Sodium Hydroxide and Potassium Hydroxide are extremely corrosive in nature and should not be touched with bare hands.
  

Uses of Bases

Caustic soda and Caustic Potash

• They are extensively used in the manufacture of soap and soap powders from vegetable oils.
• They are used in paper industry for preparing paper pulp from wood
• They are used for making artificial fibres such as rayon, Nylon, etc.
• They are used in the manufacture of medicines

Calcium oxide and Calcium Hydroxide

• They are used for neutralization of acidity of acidic soils
• Calcium Hydroxide suspension is used for white washing. A clear solution of calcium hydroxide is limewater. It is used for testing CO2 gas.
• Calcium Hydroxide is used for making mortar, which is used in construction of buildings
• Ca(OH)2 is used for removing hair from animal skins
• Ca(OH)2 is used for preparing bleaching powder

Magnesium Hydroxide and Aluminium Hydroxide

• They are used as antacids for relieving acidity in stomach. It is sold as milk of Magnesia in the market

Ammonium Hydroxide

• Used in the manufacture of fertilizers
• Used in manufacture of nitric acid
• Used in manufacture of synthetic fibres
• Used for preparation of washing soda
• Used in the preparation of organic chemical.

ACIDS

ACIDS

A substance which dissolves in water to give hydrogen ions as the only positively charged ions is called an acid. The acids prepared from the minerals of the earth are known as mineral acids.

Eg. Sulphuric Acid, Nitric Acid, Hydrochloric Acid, Phosphoric Acid.

Acids can be classified as strong and weak.

Strong Acids are acids that dissolve in water to give a large number of positively charged hydrogen ions.

Weak Acids are acids that dissolve in water to give a smaller amount of positively charged hydrogen ions.

Concenrated acids have less or no water.

Diluted acids are solutions of acids.

Natural Source	Acid
Oranges and lemons	Citric Acid
Grapes, Tamarind and Goose Berries	Tartaric acid
Tomatoes, Spinach	Oxalic Acid
Sour Milk	Lactic Acid
Vinegar	Acetic Acid
Apples	Malic Acid
Proteins	Amino Acid

Some Common Acids with their formulae

Name	Chemical Name	Formula
Hydrochloric acid	Hydrogen Chloride	HCl
Sulphuric Acid	Hydrogen Sulphate	H2SO4
Nitric Acid	Hydrogen Nitrate	HNO3
Phosphoric Acid	Hydrogen Phosphate	H3PO4
Sulphurous Acid	Hydrogen Sulphite	H2SO3
Nitrous Acid	Hydrogen Nitrite	HNO2
Carbonic Acid	Hydrogen Carbonate	HCO3

General Physical Properties of Acids :

1. They have a sour taste.
2. All acids have hydrogen atoms in them.
   
3. They turn blue litmus red.
4. They turn methyl orange solution pink
5. They donot affect phenolphthalein solution
   
6. Strong acids have a corrosive action on skin. They cause painful blisters.
   
7. Most of the acids are soluble in water.
8. Acid solutions are good conductors of electricity.

Uses of Acid :

Sulphuric acid

• Manufacture of fertilizers
• Batteries of cars, buses, trucks and inverter batteries.
• Manufacture of dyes, drugs, paints, plastics, detergents etc.

Hydrochloric Acid

• Cleaning metal surfaces during timing and galvanising
• Used in dyeing industry
• Used for preparing glucose from starch
• Used for descaling the steam boilers
• Used in cleaning kitchen sinks and other sainitary ware.

Nitric Acid

• It is used for manufacture of fertilizers such as Ammonium Nitrate and Calcium Nitrate
• It is used in manufactures of TNT and TNG.
• It is used in purification of metals such as gold and silver by goldsmiths

Phosphoric Acid

• It is used for manufacturing Phosphatic fertilizer

Carbonic Acid

• It is commonly called plain soda. Mixed with citric acid and sugar, it is used for making soft drinks.

Acetic acid

• It is used as a table acid and for the preservation of food articles

Tartaric Acid

• It is used in the manufacture of baking powder

Hydrogen Carbonates

Chemical Name	Formula
Sodium Hydrogen Carbonate	NaHCO3
Potassium Hydrogen Carbonate	KHCO3
Magnesium Hydrogen Carbonate	Mg(HCO3)2
Calcium Hydrogen Carbonate	Ca(HCO3)2

Phosphates

Name of Phosphate	Formula
Ammonium Phosphate	(NH4)3PO4
Sodium Phosphate	Na3PO4
Potassium Phosphate	K3PO4
Magnesium Phosphate	Mg3( PO4)2
Calcium Phosphate	Ca3 (PO4 )2
Aluminium Phosphate	AlPO4
Zinc Phosphate	Zn3(PO4)2