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.

If you want a more advanced version and topics in chemistry, please visit

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