Thursday, April 7, 2016

A HOMEMADE MAGNIFYING GLASS!

Lets see how we can make a magnifying glass in case of an emergency

Materials Required
  • A magazine page with small print
  • A clean empty olive bottle
  • Water
Instruction
Fill the olive jar with water to the brim. Screw on the cap. Make sure the lid is tight.
Now hold the water filled olive jar above the small printed text.
The text is now enlarged and inverted.

The water filled olive jar acts like a LENS!

Monday, March 28, 2016

HOW ARE CLOUDS FORMED???

Ever wondered how clouds are formed? Let us perform an experiment to show what happens!

Materials Required
A glass jar
Hot water
Thin cloth
Crushed ice
A rubber band

Instructions
Fill the jar with hot water. Let the glass get warm.
Stretch the cloth over the opening and wrap the rubber band around the cloth.
Place the crushed ice on top of the jar.

Observation: We observe the formation of clouds within the jar.

What is happening?
This model shows us how the clouds are formed. When warm, moist air rises from the earth, it meets the colder air higher in the atmosphere. The water vapour in the warm air condenses and form clouds.

TO PROVE THAT AIR HAS WEIGHT!

Let us look at an experiment which would prove that air actually has weight!

Materials Required

  • Two balloons
  • A ruler
  • Tape
  • String
Instructions

  1. Inflate one balloon and tape it to one end of the ruler. Don't inflate the other one and tape it to the other end.
  2. Tie a string at the middle of the ruler and tape the other and to the wall.

Observe how the ruler end with the inflated balloon attached, dips
Observation: We see that the end of the ruler, which has the inflated balloon attached dips. This suggests that there is more weight on that end than the other. But the only difference between the two balloons is that one is inflate, that is, it contains air. If we burst the balloon using a pin, we would see that neither of the ends are dipping. Thus we conclude, air has weight.

Sunday, March 27, 2016

HOW TO MAKE SOAP? HOW DOES SOAP HELP IN CLEANING?



Lets learn how to make soap! We would then go into how to soap helps us clean!

Materials Required (Please use exact measurement)


  • A soap mold
  • 24 ounce of Coconut oil
  • 24 ounces of olive oil
  • 4 ounces or 35 grams Sodium Hydroxide ( also called lye)
  • 12 ounces of cold water
  • 4 ounces of your choice of essential oil (for fragrance) like rose, cinnamon etc
  • Safety Goggles
  • Rubber Gloves
  • 2 stainless steel pots
  • 38 ounces of vegetable shortening
  • 2 Thermometers
  • Wooden spoon 

Caution: Be careful while working with sodium Hydroxide. Children to perform experiment under adult supervision only. Lye is corrosive and should be used in well ventilated areas to prevent inhalation of fumes Red warning instructions on packet.


Instructions
  1. Pour 12 ounces of water into the stainless steel pot.
  2. Slowly add lye to water, stirring gently with a spoon until the lye dissolves. Make sure the exhaust fans are on or the windows are open for ventilation. Add lye to water and not the other way around, as the reaction between the two substance would be too quick and can be dangerous. Keep your face away from the mixture to avoid inhaling the harmful fumes.
  3. The reaction would generate heat. Set the mixture aside and let it cool down.
  4. Set a large stainless steel pot on the stove on low-medium heat. Pour coconut oil, olive oil and vegetable shortening in the stove, and stir till the oils combine, then remove pot form heat.
  5. Measure the temperature and ensure that both the mixtures (the oils and the lye) are at 35°-38° Celsius and then slowly add lye to the oil mixture.
  6. Stir the mixture with a wooden spoon. DO NOT USE METAL. Continue to mix for 15-20 minutes until the spoon starts to leave “tracing” in the mixture.
  7. Now add essential oil to the mixture for fragrance.
  8. Now quickly put the mixture in the molds. Ensure you are wearing your gloves and safety goggles. Once you have poured the mixture into the mold, ensure there are no air bubbles. Cover it now.
  9. Set aside for 24 hours. Uncover the soap and set it aside for another 12 hours. If the soap has an oily film or has not set properly, it is due to inaccurate measurements and under-stirring, such a soap cannot be used.
  10. Once the soap is perfect, unmold the soap and keep it on a towel. Let it dry.
  11. Now you have the soap ready for use!!


Cleansing Action of soap.

Most of the dirt is oily in nature. We know that oil does not dissolve in water, so how do we get rid of the dirt? The answer to our problems is soap! Soap are long carboxylic chain of sodium and potassium salts. The soap molecule consists of two ends - the hydrophobic “tail” and the hydrophilic end (See figure 1). The hydrophobic tail dissolves in oil while the hydrophilic end dissolves in water. Hence one end in the soap molecule faces towards the water, while the other end face towards oil. This forms an emulsion in water. This structure is called micelles(See figure 2). Soap in the form of micelles is able to clean dirt.

SOAP MOLECULE (FIG 1)

MICELLES (FIG 2)


The hydrophobic end is always kept away from water. Inside water the soap molecules form clusters, in which the hydrophobic end is in the interior.

Why does the soap solution appears to be cloudy?
The micelles are large enough to scatter light, hence soap solution appears to be cloudy