Students Chemistry

About Us

noreply@blogger.com (Anshul) — Fri, 29 Feb 2008 15:00:00 +0530

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

More http://chemistry.about.com/

Elements

noreply@blogger.com (Anshul) — Fri, 29 Feb 2008 14:59:00 +0530

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

noreply@blogger.com (Anshul) — Fri, 29 Feb 2008 14:58:00 +0530

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

noreply@blogger.com (Anshul) — Fri, 29 Feb 2008 14:57:00 +0530

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

noreply@blogger.com (Anonymous) — Fri, 29 Feb 2008 14:56:00 +0530

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

noreply@blogger.com (Anonymous) — Fri, 29 Feb 2008 14:54:00 +0530

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

noreply@blogger.com (Anshul) — Fri, 29 Feb 2008 02:55:00 +0530

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 :

They have a sour taste.
All acids have hydrogen atoms in them.
They turn blue litmus red.
They turn methyl orange solution pink
They donot affect phenolphthalein solution
Strong acids have a corrosive action on skin. They cause painful blisters.
Most of the acids are soluble in water.
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

noreply@blogger.com (Anonymous) — Thu, 28 Feb 2008 16:49:00 +0530

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

Phosphates

noreply@blogger.com (Anshul) — Thu, 28 Feb 2008 16:46:00 +0530

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

Carbonates

noreply@blogger.com (Anshul) — Thu, 28 Feb 2008 16:45:00 +0530

Name of Carbonate	Formula
Ammonium Carbonate	(NH₄)₂ CO₃
Sodium Carbonate	Na₂CO₃
Potassium Carbonate	K₂CO₃
Calcium Carbonate	CaCO₃
Magnesium Carbonate	MgCO₃
Aluminium Carbonate	Al₂(CO₃)₃
Zinc Carbonate	ZnCO₃
Iron Carbonate	FeCO₃
Lead Carbonate	PbCO₃
Copper Carbonate	CuCO₃

Sulphates

noreply@blogger.com (Anonymous) — Thu, 28 Feb 2008 16:44:00 +0530

Name Of Sulphate	Formula
Ammonium Sulphate	(NH4)₂SO₄
Sodium Sulphate	Na₂SO₄
Potassium Sulphate	K₂SO₄
Calcium Sulphate	CaSO₄
Magnesium Sulphate	MgSO₄
Zinc Sulphate	ZnSO4
Aluminium Sulphate	Al₂(SO₄)₃
Iron Sulphate	FeSo₄
Lead Sulphate	PbSO₄
Copper Sulphate	CuSO₄
Mercury Sulphate	HgSO₄
Silver Sulphate	Ag₂SO₄

Nitrates

noreply@blogger.com (Anonymous) — Thu, 28 Feb 2008 16:42:00 +0530

Name Of Nitrate	Formula
Ammonium Nitrate	NH₄NO₃
Sodium Nitrate	NaNO₃
Potassium Nitrate	KNO₃
Calcium Nitrate	Ca(NO₃)₂
Magnesium Nitrate	Mg(NO₃)₂
Aluminium Nitrate	Al(NO₃)₃
Zinc Nitrate	Zn(NO₃)₂
Iron Nitrate	Fe(NO₃)₂
Lead Nitrate	Pb(NO₃)₂
Copper Nitrate	Cu(NO₃)₂
Mercury Nitrate	Hg(NO₃)₂
Silver Nitrate	AgNO₃

Chloride

noreply@blogger.com (Anshul) — Thu, 28 Feb 2008 16:41:00 +0530

Name Of Chloride	Formula
Ammonium Chloride	NH₄Cl
Sodium Chloride	NaCl
Potassium Chloride	KCl
Calcium Chloride	CaCl₂
Magnesium Chloride	MgCl₂
Aluminium Chloride	AlCl₃
Zinc Chloride	ZnCl₂
Iron Chloride	FeCl₂
Copper Chloride	CuCl₂
Silver Chloride	AgCl

Oxides

noreply@blogger.com (Anshul) — Thu, 28 Feb 2008 16:40:00 +0530

Name Of Oxide	Formula
Sodium oxide	Na₂O
Potassium Oxide	K₂O
Magnesium Oxide	MgO
Calcium Oxide	CaO
Aluminium Oxide	Al₂O₃
Zinc Oxide	ZnO
Iron Oxide	FeO
Lead Oxide	PbO
Copper Oxide	CuO
Mercury Oxide	HgO

Hydroxides

noreply@blogger.com (Anshul) — Thu, 28 Feb 2008 16:39:00 +0530

Chemical Name	Formula
Ammonium Hydroxide	NH₄OH
Sodium Hydroxide	NaOH
Potassium Hydroxide	KOH
Calcium Hydroxide	Ca(OH)₂
Magnesium Hydroxide	Mg(OH)₂
Aluminium Hydroxide	Al(OH)₃
Zinc Hydroxide	Zn(OH)₂

Indicators

noreply@blogger.com (Anshul) — Wed, 27 Feb 2008 13:14:00 +0530

In chemistry, natural or synthetic substance that changes color in response to the nature of its chemical environment. Indicators are used to provide information about the degree of acidity of a substance (pH) or the state of some chemical reaction within a solution being tested or analyzed. One of the oldest indicators is litmus, a vegetable dye that turns red in acid solutions and blue in basic ones. Other indicators include alizarin, methyl red, and phenolphthalein, each one being useful for a particular range of acidity or a certain type of chemical reaction.

Litmus, vegetable dye obtained from lichens, usually of the genus Variolaria, and used in chemistry to determine the presence of acids and bases in a solution. Strips of paper impregnated with a blue or red litmus solution, or small quantities of the solution itself, are used to indicate the presence of an acid or a base; acids turn blue litmus red, and bases turn red litmus blue.

pH, term indicating the hydrogen ion (positively charged hydrogen atom) concentration of a solution, a measure of the solution’s acidity. Hydrogen ions are usually represented by the symbol H⁺. The term (from French pouvoir hydrogène, “hydrogen power”) is defined as the negative logarithm of the concentration of H⁺ ions: pH = -log₁₀[H⁺], where [H⁺] is the concentration of H⁺ ions in moles per litre. Because H⁺ ions associate with water molecules to form hydronium (H₃O⁺) ions, pH also is often expressed in terms of the concentration of hydronium ions.

Chemical Reaction

noreply@blogger.com (Anshul) — Wed, 27 Feb 2008 13:14:00 +0530

When one or more substances undergo a chemical change, with the absorption or release of energy, so as to form one or more new products, then the change taking place collectively is called chemical reaction.

In a chemical reaction, the substance(s) which take part in bringing about a chemical change are called reactants.

The substance(s) which are produced as a result of chemical change are called products.

Conditions for a chemical reaction

There must be one or more substances to take part in a chemical reaction.
There must be absorption or release of energy during a chemical reaction.
At least one substance should be formed during a chemical reaction.

Evolution of a gas

Some chemical reactions are characterised by the evolution of a gas. For eg. when baking soda( Sodium Hydrogen Carbonate - NaHCO₃) is treated with vinegar( Acetic Acid - CH₃COOH), it gives off colourless Carbon dioxide( CO₂ ) gas, with a lot of effervescence( bubbly). It can be represented as :
NaHCO₃+ CH₃COOH CH₃COONa + H₂O + CO₂CH₃COONa is Sodium Acetate.

Change of colour

Some chemical reactions are characterised by the change of colour of reactants. For eg. when copper carbonate( green colour - CuCO3) is heated strongly, it leaves behind a black residue of copper copper oxide( CuO) and gives off Carbon dioxide( CO₂ ). It can be represented as

CuCO3CuO + CO2

Formation of precipitate (ppt)

Some chemical reactions are characterised by the formation of a precipitate( an insoluble substance), when the solutions of two chemical compounds are mixed together. For eg. a white precipitate of silver chloride is formed when a colourless solution of silver nitrate is mixed with a colourless solution of sodium chloride. It can be represented as

AgNO₃(Solution) + NaCl(Solution) NaNO₃(Solution) + AgCl(White Precipitate)

Energy Changes

Some chemical reactions are characterised by the release or absorption of energy. For eg. when a small piece of quick lime(calcium oxide - CaO) is placed in about 100 cc of water, the water becomes very hot and sometimes start boiling. It is because, the calcium oxide(CaO) reacts with water to form calcium hydroxide with the release of heat energy. It can be represented as

CaO + H₂O Ca(OH)₂ + Heat Energy

Change of State

Some chemical reactions are characterised by the change of state. For eg. Ammonia gas(NH3 - Hydrogen Nitride) reacts with Hydrochloric acid(HCl - Hydrogen Chloride) gas to form dense white fumes of ammonium chloride(NH₄Cl), which is in the solid state. It can be represented as

NH3 + HCl Solid NH₄Cl

Types of Chemical Reactions

Chemical Combination/Composition - When two or more elements or compounds react chemically to form only one new product, then the reaction which takes place is called chemical combination.

Examples

When a mixture of iron fillings and sulphur is heated strongly, it reacts to form iron sulphide(FeS). It can be represented as

Fe + S FeS

When quicklime(CaO) is mixed with water, it reacts to form a single new product, calcium hydroxide(Ca(OH)_{2). It can be represented as}CaO + H₂O Ca(OH)_{2

Note : Heat energy is also released during this reaction. Heat is an energy and so is not considered as a product.

Chemical Decomposition/Decombination - When a single chemical compound decomposes on heating or by some other kind of energy, so as to form two or more new substances, then the chemical reaction which takes place is called chemical decomposition.

Examples

Mercury oxide(HgO) on strong heating decomposes to form mercury(Hg) and oxygen(O). It can be represented as

HgO}Hg + O

When marble chips(Calcium Carbonate - CaCO3) are heated strongly, they decompose to form Calcium Oxide(CaO) and Carbon Dioxide(CO_{2). It can be represented as}
CaCO3CaO + CO2

Chemical Displacement/Replacement - When a more reactive element displaces a less reactive element from its aqueous salt solution(from its water solution), the reaction which takes place is known as chemical displacement.

There is a list of reactivity of common elements. It is given below in the 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.

Examples

Iron(Fe), reacts with copper sulphate(CuSO4) solution to displace Copper(Cu - Because its less reactive than Iron) and forms a solution of iron sulphate(FeSO4).It can be represented as

Fe + CuSO4(Solution) FeSO4 + Cu.

Zinc(Zn) reacts with dilute Sulphuric Acid(H₂SO₄ - Hydrogen Sulphate) to displace Hydrgen(H - Less Reactive) and form a solution of Zinc Sulphate(ZnSO_{4).

Zn +}H₂SO4(Dilute) ZnSO4 + H

Salts

noreply@blogger.com (Anshul) — Wed, 27 Feb 2008 13:13:00 +0530

Salts- Water of Crystalization

Crystals of some salts have some fixed amount of water molecules attached to them. Such salts are called hydrated salts and the water molecules attached to them are called water of crystallization.

On heating the hydrated salts lose their water molecules( water of crystallization). In doing so they lose their colour and shape and form a powdery substance. The compound left after heating is called anhydrous salt. Anhydrous regain the colour after the addition of water for eg. Copper Sulphate loses its blue colour after heating and regains its colour after addition of water.

The water of crystallization is always mentioned after a dot(.) for eg. Copper Sulphate is CuSO₄.5H₂O.

USES OF SALTS IN DAILY LIFE

1. Common Salt [NaCl] : It is used as table salt. It is used for preservation of food in pickling. It is used to preserve raw hides. It is used in the manufacture of chemicals such as chlorine, caustic soda (NaOH) and washing soda (Na₂CO₃).

2. Baking Soda [NaHCO₃] : It is used for making baking powder. It is used for preparing antacid tablets, for controlling acidity in the stomach.

3. Washing Soda [Na₂CO₃] : It is used by washermen to wash clothes. It is used in manufacture of glass and caustic soda. It is used in fire extinguishers. It is used in the manufacture of detergents.

4. Chile Salt Petre [(NH₄)₂CO₃] : It is used in the manufacture of nitric acid, gun powder and fire works.

5. Nitre [KNO₃] : It is used as a fertilizer. It is also used in the manufacture of gun powder, fire works and Nitric acid.

6. Smelling salt [(NH₄)₂CO₃] : It provides relief from common cold.

7. Epsom Salt [MgSO₄] : It is used as a laxative by patients suffering from constipation.

8. Green Vitriol [FeSO₄.5H₂O] : It is used in making blue – black inks and in curing leather.

9. Blue Vitriol [CuSO₄.5H₂0] : It is used as fungicide in agriculture. It is used in dyeing and printing industry. It is used in electroplating copper metal.

10. Plaster of Paris [CaSO₄.1/2H₂O] : It is used for making statues. It is used for setting broken bones.

11. Potash alum [K₂SO₄.Al₂(SO₄)₃.24H₂O] : It helps in rapid settling of suspended impurities in water. It is used for the purification of water.

Hydrocarbons

noreply@blogger.com (Anshul) — Wed, 27 Feb 2008 13:12:00 +0530

Hydrocarbons are nothing but organic compounds consisting entirely of Hydrogen and Carbon. Hydrocarbons come under a different branch of Chemistry – Organic Chemistry.

Organic Chemistry – An Introduction

Carbon unites with many elements to form a great variety of compounds that are found in such substances as coal, petroleum, fabrics, plastics, and rubber. Other carbon compounds include plant and animal tissues, sugars, proteins, starches, and cellulose. About 1 million carbon compounds are known. The substances that contain carbon are called organic compounds, and the science that deals with them is known as organic chemistry.

This name arose because chemists once thought that many of these compounds could be formed only by a vital force (a life process). This was disproved in 1828 when the German chemist Friedrich Wöhler converted the compound ammonium cyanate, NH₄CNO, into urea (NH₂)₂CO.

Before this, urea had been known only as a product of life processes. Today chemists can make many of the products that formerly had been produced only by living plants and animals.

Carbon compounds exist in such number and variety because of the chemical properties of carbon. Since carbon is in Group IV A of the periodic table, it appears to be midway between the metals and nonmetals and has the ability to react with both types of elements. The structure of the carbon atom is unique among atoms, allowing a great array of compounds that are stable under normal atmospheric conditions and reactive in other situations. Carbon reacts as follows:

1. Carbon atoms have the unusual property of combining with each other to form rings or long chains. No other element does so as extensively.

2. Carbon will combine with many different atoms or groups of atoms. This property, together with the ability to form long chains, makes carbon the most versatile of all elements in forming compounds.

3. Carbon forms many compounds that exist as isomers. Isomers are molecules with the same number and kinds of atoms, but in different arrangements.

Let’s get back to Hydrocarbons.

Hydrocarbons are one of the most important energy resources of the Earth. The main usage is as a combustible fuel source.

Hydrocarbons are currently the main source of the world’s electric energy and heat sources (such as home heating) because of the energy produced when burnt. Often this energy is used directly as heat such as in home heaters, which use either oil or natural gas. The hydrocarbon is burnt and the heat is used to heat water, which is then circulated. A similar principle is used to create electric energy in power plants.

As methane only releases one carbon dioxide for two water molecules, it is considered the cleanest fuel.

Liquid geologically-extracted hydrocarbons are referred to as petroleum (literally "rock oil") or mineral oil, while gaseous geologic hydrocarbons are referred to as natural gas. All are significant sources of fuel and raw materials as a feedstock for the production of organic chemicals and are commonly found in the Earth's subsurface using the tools of petroleum geology.

The extraction of liquid hydrocarbon fuel from a number of sedimentary basins has been integral to modern energy development. Hydrocarbons are mined from tar sands, oil shale and potentially extracted from sedimentary methane hydrates. These reserves require distillation and upgrading to produce synthetic crude and petroleum.

Oil reserves in sedimentary rocks are the principal source of hydrocarbons for the energy, transport and petrochemical industries. Hydrocarbons are of prime economic importance because they encompass the constituents of the major fossil fuels (coal, petroleum, natural gas, etc.) and plastics, paraffin, waxes, solvents and oils.

Activity #1 - Smoke Bomb

noreply@blogger.com (Anshul) — Wed, 27 Feb 2008 13:11:00 +0530

Some people are fascinated by smoke bombs and want to make or own one. If you like want to have one, then don't worry. A safe, simple smoke bomb is ready in a few hours.

Lets Get Experimenting.

Smoke Bomb Materials

The smoke bomb you would purchase from a fireworks store usually is made from potassium chlorate (KClO₃ - oxidizer), sugar (sucrose or dextrin - fuel), sodium bicarbonate (otherwise known as baking soda - to moderate the rate of the reaction and keep it from getting too hot), and a powdered organic dye (for colored smoke). When a commercial smoke bomb is burned, the reaction makes white smoke and the heat evaporates the organic dye. Commercial smoke bombs have small holes through which the smoke and dye are ejected, to create a jet of finely dispersed particles. Crafting this type of smoke bomb is beyond most of us, but you can make an effective smoke bomb quite easily. There are even colorants you can add if you want to make colored smoke. Let's start out with instructions for the easiest/safest type of smoke bomb you can make:

Smoke Bomb Materials

sugar (sucrose or table sugar)
potassium nitrate, KNO₃, also known as saltpeter (you can find this at some garden supply stores in the fertilizer section, some pharmacies carry it too)
skillet or pan
aluminum foil

Once you've gathered your smoke bomb materials, it's easy to make one.

The bomb after making looks like this.

Lets make it.

How to Make a Smoke Bomb

Pour about 3 parts potassium nitrate to 2 parts sugar into the skillet (5:3 ratio is also good). Measurements don't need to be exact, but you want more KNO₃ than sugar. For example, you can use 1-1/2 cups KNO₃ and 1 cup sugar. If you use equal amounts of KNO₃ and sugar, your smoke bomb will be harder to light and will burn more slowly. As you approach the 5:3 KNO₃:sugar ratio, you get a smoke bomb that burns more quickly.
Apply low heat to the pan. Stir the mixture with a spoon using long strokes. If you see the grains of sugar starting to melt along the edges where you are stirring, remove the pan from the heat and reduce the temperature before continuing.
Basically you are carmelizing sugar. The mixture will melt and become a caramel or chocolate color. Continue heating/stirring until the ingredients are liquefied. Remove from heat.
Pour the liquid onto a piece of foil. You can pour a smaller amount onto a separate piece, to test the batch. You can pour the smoke bomb into any shape, onto an object, or into a mold. The shape and size will affect the burning pattern.
If you aren't going to clean your skillet immediately, pour hot water into the pan to dissolve the sugar (or else it will be harder to clean). Clean up any residue you may have spilled out of the pan, unless you want mini-smoke bombs on your stove top.
Allow the smoke bomb to cool, then you can peel it off the foil.

How to Use a Smoke Bomb

The solid smoke bomb material is flammable and can be lit directly. You can light your smoke bomb using a lighter, preferably one of the long-handled types used for barbeque grills. Only light your smoke bomb in a well-ventilated area, on a surface that won't catch fire. The smoke bomb will burn vigorously (more slowly with a higher percentage of sugar) with a purple flame.

Alternatively, you could place a short length of wick into the smoke bomb when you pour it, and then light the wick.

Make Colored Smoke Bombs

The recipes for colored smoke bombs require chemicals that may not be readily available unless you have access to a chemistry lab, but it's worth knowing how it's done. Parts or percents are by weight. The ingredients are sifted together and ignited to produce the smoke.

White Smoke Recipe

Potassium nitrate - 4 parts
Charcoal - 5 parts
Sulfur - 10 parts
Wood dust - 3 parts

Red Smoke Recipe

Potassium chlorate - 15%
para-nitroaniline red - 65%
Lactose - 20%

Green Smoke Recipe

Synthetic indigo - 26%
Auramine (yellow) - 15%
Potassium chlorate - 35%
Lactose - 26%

White Smoke Bomb with Colored Flames

It's fairly easy to make colored flames by adding these chemicals to your smoke bomb recipe:

Chemicals Used to Color Flames

Red - strontium salts, most easily found in road flares
Orange - calcium chloride (laundry bleaching agent)
Yellow - sodium nitrate (common in chemistry lab)
Green - barium salts, such as barium nitrate (common in chemistry lab)
Greenish-Blue - copper sulfate (common in a chemistry lab, also found in many algicides for pool treatment) Blue - copper chloride (common in chemistry lab)
Purple - potassium permanganate (common in a chemistry lab, also used in sewage or water treatment)
White - magnesium sulfate (epsom salts, found on laundry aisle or in a pharmacy)

Essentially, you are adding metal salts to get colored flames. You may get additional ideas from looking at the Flame Tests, Fireworks Colors, and How to Color Fire tables. The metal salts listed here produce a relatively safe smoke. Use caution when considering other metals salts, as some compounds may produce toxic smoke.

Activity #2 - Colour Flames - Simple to make

noreply@blogger.com (Anshul) — Wed, 27 Feb 2008 13:10:00 +0530

Fun Fireplace Instructions

I know I'm not the only person who has rummaged through old magazines and newspapers, looking for highly colored pages to throw onto a fire to make colored flames. This method of coloring fire, while fun, is hit-and-miss. Have you ever wanted to know how to color the fire reliably? I've compliled a list of colorants and simple instructions for using them. Here are some of your options:

Toss dry colorants onto the flames.
Soak logs in an alcohol solution of colorants.
Soak logs in an aqueous (water) solution of colorants and allow the logs to dry.
Prepare pinecones, sawdust, or cork with colorants.

In general, there is no specific proportion of colorant to mix with the water or alcohol. Add as much powdered colorant as will dissolve in the liquid (roughly a half pound colorant to a gallon of water). Do not attempt to mix colors together - you will probably end up with a normal yellow flame. If you want multicolored fire, try adding several pinecones, each treated with a single colorant, or scatter a mixture of dried colored sawdusts across the fire.

How to Prepare Pinecones or Sawdust

It's easy! Remember to do this procedure separately for each color. You can combine dry pinecones or sawdust with different colorants later.

Pour water into a bucket. Use sufficient water to be able to wet your pinecones, sawdust, or waste cork. Skip to step 3 if you purchased your colorant in liquid form.
Stir in colorant until you can't dissolve any more. For sawdust or waste cork, you may also add some liquid glue, which will allow the pieces to stick together and form larger chunks.
Add the pinecones, sawdust, or cork. Mix to form an even coat.
Let the material soak in the colorant mixture for several hours or overnight.
Spread the pieces out to dry. If desired, pinecones may be placed in a paper or mesh bag. You can spread sawdust or cork out on paper, which will also produce colored flames.

How to Prepare Logs

Follow steps 1 and 2 above and either roll a log around in the container (big container, small log) or else pour and spread the mixture onto the logs. Wear kitchen or other protective gloves to protect your hands. Allow the logs to dry. If you make your own newspaper logs, you can smear colorant onto the paper before rolling it.

Points to Keep in Mind

The element sodium burns with the usual yellow flame. The presence of this element can overwhelm any other color. If you are making a dry mixture of colorants or colored pinecones/sawdust, you should avoid including any colorant that has sodium in it.
If you are using alcohol-based colorants: Remember that alcohol is flammable. If you don't allow it to evaporate before use, you will get a lighter-fluid effect. Use with care!
Don't color BBQ fire! The colorants may produce pretty flames, but they can also produce toxic food.
Keep the colorants away from children and handle them with the care and respect due to potentially hazardous chemicals. Read and adhere to any warnings listed on product labels.

Now, here is the list of colorants. Most can be found in a grocery or dry goods store, in the laundry or cleaner section. Look for copper sulfate in swimming pool supplies (already in water, which is fine). Potassium chloride is used as a salt substitute and may be found in the spice section. Epsom salts, borax, and calcium chloride may be found with laundry/cleaning supplies. Others, including strontium chloride, can be obtained from stores that specialize in rocketry or firework supplies.

Flame Colorants

Color	Chemical
Carmine	Lithium Chloride
Red	Strontium Chloride
Orange	Calcium Chloride (a bleaching powder)
Yellow	Sodium Chloride (table salt) or Sodium Carbonate
Yellowish Green	Borax
Green	Copper Sulfate
Blue	Copper Chloride
Violet	3 parts Potassium Sulfate 1 part Potassium Nitrate (saltpeter)
Purple	Potassium Chloride
White	Magnesium Sulfate (Epsom salts)

The result looks like this :

Activity #3 - Stainless colour soap bubbles

noreply@blogger.com (Anshul) — Wed, 27 Feb 2008 13:09:00 +0530

Difficulty: Easy

Time Required: Only Takes a Few Minutes

Here's How:

If you are making your own bubble solution, mix the detergent and water.
Add the sodium hydroxide and indicator to the bubble solution. You want enough indicator so that the bubbles will be deeply colored. For each liter of bubble solution (4 cups) this is about 1-1/2 to 2 teaspoons of phenolphthalein (red) or thymolphthalein (blue).
Add sodium hydroxide until you get the indicator to change from colorless to colored (about half a teaspoon should do the trick). A little more sodium hydroxide will result in a bubble that stays colored longer. If you add too much, the color of the bubble won't disappear when exposed to air or rubbed, though you can still react it with club soda.
You may find it necessary to dissolve the indicator in a small amount of alcohol before mixing it with the bubble solution. You can use pre-made indicator solution, adding the sodium hydroxide to the indicator rather than diluting with water.
You've essentially made disappearing ink bubbles. When the bubble lands, you can make the color vanish by either rubbing the spot (reacting the liquid with air) or by adding a little club soda. Fun!
If you have disappearing ink, you could mix it with bubble solution to make disappearing ink bubbles.

Tips:

Please don't drink the bubble solution! Unused bubble solution may be stored for later in a sealed container or disposed of by pouring it down the drain.
These are bubbles intended for 'blowing bubbles', not for bathing.
Sodium hydroxide is a strong base. Avoid direct contact with this ingredient. If you do get some on your hands, rinse them immediately with water.
Phenolphthalein and thymolphthalein change from red or blue to uncolored around pH=10. If you look on the indicator chart, you can see there are several less common indicators that would change color rather than disappear at this pH.

What You Need:

Liquid Dishwashing Detergent (or other detergent)
Water
or Commercial Bubble Solution
Sodium Hydroxide
Phenolphthalein
Thymolphthalein
Club Soda (optional)

noreply@blogger.com (Anshul) — Wed, 27 Feb 2008 13:09:00 +0530

Activity #4 - Burning Money - No Loss or Damage

noreply@blogger.com (Anshul) — Wed, 27 Feb 2008 13:08:00 +0530

NOTE : THIS WORKS ONLY WITH DOLLAR($) PAPER

Burning Money Chemistry Demonstration

This is a neat 'magic trick' that illustrates the process of combustion, the flammability of alcohol, and the special qualities of the material used to make currency.

Scientific Concept behind Burning Money

A combustion reaction occurs between alcohol and oxygen, producing heat and light (energy) and carbon dioxide and water.

C₂H₅OH + 4 O₂ -> 2 CO₂ + 3 H₂O + energy

When the bill is soaked an alcohol-water solution, the alcohol has a high vapor pressure and is mainly on the outside of the material (a bill is more like fabric than paper, which is nice, if you've ever accidentally washed one). When the bill is lit, the alcohol is what actually burns. The temperature at which the alcohol burns is not high enough to evaporate the water, which has a high specific heat, so the bill remains wet and isn't able to catch fire on its own. After the alcohol has burned, the flame goes out, leaving a slightly damp dollar bill.

Burning Money Chemistry Demonstration

This is a neat 'magic trick' that illustrates the process of combustion, the flammability of alcohol, and the special qualities of the material used to make currency.

Scientific Concept behind Burning Money

A combustion reaction occurs between alcohol and oxygen, producing heat and light (energy) and carbon dioxide and water.

C₂H₅OH + 4 O₂ -> 2 CO₂ + 3 H₂O + energy

Materials for Burning Money Demonstration

Here is what you need to perform the burning money demonstration:

dollar bill (higher denomination if you're brave)
tongs
matches or a lighter
salt (or one of these chemicals if you want a colored flame)
solution of 50% alcohol and 50% water (you can mix 95% alcohol with water in a 1:1 ratio, if desired)

Have you gathered your materials? Let's burn it.

Procedure for Burning Money Demonstration

Prepare the alcohol and water solution. You can mix 50 ml of water with 50 ml of 95-100% alcohol.
Add a pinch salt or other colorant to the alcohol/water solution, to help produce a visible flame.
Soak a dollar bill in the alcohol/water solution so that it is thoroughly wet.
Use tongs to pick up the bill. Allow any excess liquid to drain. Move the damp bill away from the alcohol-water solution.
Light the bill on fire and allow it to burn until the flame goes out.

Activity #5 - Bend a stream of flowing water

noreply@blogger.com (Anshul) — Wed, 27 Feb 2008 13:07:00 +0530

When two objects are rubbed against each other, some of the electrons from one object jump to the other. The object that gains electrons becomes more negatively charged; the one that loses electrons becomes more positively charged. The opposite charges attract each other in a way that you can actually see.

One way to collect charge is to comb your hair with a nylon comb or rub it with a balloon. The comb or balloon will become attracted to your hair, while the strands of your hair (all the same charge) repel each other. The comb or balloon will also attract a stream of water, which carries an electrical charge.

Difficulty: Easy

Time Required: minutes

Here's How:

Comb dry hair with a nylon comb or rub it with an inflated latex balloon.
Turn on the tap so that a narrow stream of water is flowing (1-2 mm across, flowing smoothly).
Move the balloon or teeth of the comb close to the water (not in it). As you approach the water, the stream will begin to bend toward your comb.
Experiment! Does the amount of 'bend' depend on how close the comb is to the water? If you adjust the flow, does it affect how much the stream bends? Do combs made from other materials work equally well? How does a comb compare with a balloon? Do you get the same effect from everyone's hair or does some hair release more charge than others? Can you get your hair close enough to the water to repel it without getting it wet?

Tips:

This activity will work better when the humidity is low. When humidity is high, water vapor catches some of the electrons that would jump between objects. For the same reason, your hair needs to be completely dry when you comb it.

What You Need:

water faucet
nylon comb or latex balloon