"Where there's smoke, there's fire"

For long it has been said that where there's smoke, there's fire. That all was before the age of chemistry. Now its not a hard job to produce some nice thick white smoke without any fire at all.

You only need concentrated ammonia and concentrated hydrochloric acid solution. Dilutes will also work. If you do not have access to a laboratory or chemicals, you can get the hydrochloric acid in the open market as muriatic acid(cleaning agent) and ammonia in blue print shops.

Soak two pieces of cotton wool in each solution and keep them beside each other and experience the holy smoke.

What actuallly happens is hydrogen chloride gas evolved from hydrochloric acid and ammonia evaporated from ammonia solution comes in contact each other in mid-air and forms fine particles of ammonium chloride, which constitutes the smoke.

Glittering golden crystals at your disposal

Things you'll require:
1. Lead nitrate
2. Potassium iodide
3. Test tubes and a heat source

How to do it:
Take little amount(1/100th of a teaspoon-full, you get the idea) of lead nitrate and potassium iodide into two test tubes and add little water to it(1/10th of test tube). Now pour one solution into another one. You will instantly notice separation of some yellow solid. Now gradually heat and shake the mixture using a heat source(gas burner, spirit lamp etc). The yellow solid dissolves. Now stop heating and let it cool down. Observe. You'll see tiny golden glittering particles forming in the solution. Cool with tap water for an instant effect!

Why? Lead nitrate and potassium iodide reacts to form lead iodide, which is soluble in water at higher temperatures but recrystallizes on cooling.

Caution: Lead nitrate as well as lead iodide is toxic. So handle carefully.

How to clean old oil paintings

Do you have an old oil painting lying in your backyard which you suspect looked good many years ago? If you observe those old oil paintings, you'll find many black spots - they are the black lead sulphide, which is the result of the reaction between airborne hydrogen sulphide and the paints.

You can easily remove those black marks and get a modestly fair painting from your old one.

Things you'll require:

1. Cotton wool
2. Hydrogen peroxide solution (Can be found at medical stores)


How to do it:
Soak the cotton wool in the hydrogen peroxide solution and rub it gently all over the paint. The discolored and black spots will go away.


Why? Lead sulphide is oxidized by hydrogen peroxide to colorless lead sulphate, which removes the spots.

This is just a very basic method and should only be used for educational or fun purposes, never for recovering serious paintings.

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