| What you need: an exhausted dry battery salt water candle nail and hammer |
Punch 3 small holes at the bottom of the battery. Make sure that the holes are distributed uniformly around the centre of the bottom. Dissolve some salt in the water, and pour it into the holes, carefully. Be sure that the holes is full filled with the solution. After that, seal up the holes with the candle. When tested, you will find that the power of the battery has been recovered.
Reason:
The electric power of a dry battery comes from the electrolisis happening in it. The battery is exhausted because the electrolite has run out. Therefore, the salt water is used to act as the electrolite.
| What you need: an egg vinegar water |
Soak the egg in vinegar treatment until the shell has become soft. Pour out the vinegar, and soak the egg in plain water. In a few days the egg will have become so large that the shell will burst.
Reason:
The acid in the vinegar combines with the calcium in the egg shell, making the shell soft. When the egg is then immersed in water, the water will go through the shell in to the egg until the shell burst. This is the principle of osmosis, in which a less concentrated solution will go through a membrane into a more concentrated solution more than in the reverse direction.
| What you need: a copper cent vinegar a plate salt |
Sprinkle a little salt on the coin and pour on some vinegar. The coin will be cleaned beautifully. However, after some time, the copper coin will begin to corrode and turn green.
Reason:
Here is a little simple chemistry. Salt (sodium chloride) plus hydrogen acetate in the vinegar gives us sodium acetate plus hydrogen chloride (hydrochloric acid).
The hydrochloric acid is strong, and if the bronze cent comes into contact with it and the newly formed salt (sodium acetate), it is cleaned rapidly.
The cleaning process leaves the surface in porous active condition so that it quickly corrodes by combining with water, and oxygen and carbon dioxide in the air.
| What you need: a dish vinegar water some pieces of coal or small porous stones salt |
Place the pieces of coal in the dish. Pour salt into warm water and stir until no more salt will dissolve. Put a spoonful of vinegar in the water, and pour it over the pieces of coal in the dish. In a few days, the salt will begin to "grow" and eventually will cover the pieces of coal in beautiful crystals.
Reason:
The salt water flows up through and over the pieces of coal because of capillary action. As it rises it evaporates leaving the salt behind. The vinegar serves to take away oily spots on the pieces of coal that would interfere with the free upward flow of the salt water.
If the solution is left in an open glass the crystals will begin to form above the solution. Crystals there will act as capillaries, allowing more liquid to flow up. This may continue until there is "growth" of the crystals up and over the edge of the glass.
| What you need: a bottle with a cork vinegar water baking soda a pan or sink to catch the overflow |
Put water and vinegar into the bottle. Roll a little baking soda in the paper (tissue is best). Drop the paper into the bottle, put the cork on, and soon the cork will pop out.
Reason:
When the acid of the vinegar and the baking soda are allowed to mix, they combine chemically to produce carbon dioxide gas. The pressure of the gas as it is formed blows out the cork.
Corks may be hard to get. Try this without the cork; the water and bubbles will overflow. Do not use a screw-top bottle.