cse preliminiary preparation - தமிழில்

cse  preliminiary  preparation  - தமிழில்



கர்நாடக போர்கள் - தமிழில்

கர்நாடக போர்கள்  - தமிழில்

இலவசமாக டோவ்ன்லோடு   செய்ய இங்கே கிளிக் செய்யவும் :

                                              KARNATIC WARS - TAMIL MP3


Rapid Color Changing Chemistry!

Rapid Color Changing Chemistry! 


(The Elephant's Toothpaste Experiment)
  • A clean 16 ounce plastic soda bottle
  • 1/2 cup 20-volume hydrogen peroxide liquid (20-volume is a 6% solution, ask an adult to get this from a beauty supply store or hair salon)
  • 1 Tablespoon (one packet) of dry yeast
  • 3 Tablespoons of warm water
  • Liquid dish washing soap
  • Food coloring
  • Small cup
  • Safety goggles

NOTE: As you can see from the picture, foam will overflow from the bottle, so be sure to do this experiment on a washable surface, or place the bottle on a tray.
1. Hydrogen peroxide can irritate skin and eyes, so put on those safety goggles and ask an adult to carefully pour the hydrogen peroxide into the bottle.

2. Add 8 drops of your favorite food coloring into the bottle.

3. Add about 1 tablespoon of liquid dish soap into the bottle and swish the bottle around a bit to mix it.

4. In a separate small cup, combine the warm water and the yeast together and mix for about 30 seconds.
5. Now the adventure starts! Pour the yeast water mixture into the bottle (a funnel helps here) and watch the foaminess begin!

Foam is awesome! The foam you made is special because each tiny foam bubble is filled with oxygen. The yeast acted as a catalyst (a helper) to remove the oxygen from the hydrogen peroxide. Since it did this very fast, it created lots and lots of bubbles. Did you notice the bottle got warm. Your experiment created a reaction called an Exothermic Reaction - that means it not only created foam, it created heat! The foam produced is just water, soap, and oxygen so you can clean it up with a sponge and pour any extra liquid left in the bottle down the drain.
This experiment is sometimes called "Elephant's Toothpaste" because it looks like toothpaste coming out of a tube, but don't get the foam in your mouth!

The project above is a DEMONSTRATION. To make it a true experiment, you can try to answer these questions:
1. Does the amount of yeast change the amount of foam produced?
2. Does the experiment work as well if you add the dry yeast without mixing it with water?
3. Does the size of the bottle affect the amount of foam produced?


Chemistry Project - Red Cabbage pH Indicator

How to Make Red Cabbage pH Indicator  

Red cabbage contains a pigment molecule called flavin (an anthocyanin). This water-soluble pigment is also found in apple skin, plums, poppies, cornflowers, and grapes. Very acidic solutions will turn anthocyanin a red color. Neutral solutions result in a purplish color. Basic solutions appear in greenish-yellow. Therefore, it is possible to determine the pH of a solution based on the color it turns the anthocyanin pigments in red cabbage juice.
The color of the juice changes in response to changes in its hydrogen ion concentration. pH is the -log[H+]. Acids will donate hydrogen ions in an aqueous solution and have a low pH (pH < 7). Bases accept hydrogen ions and have a high pH (pH > 7).


Project - III

Soil Permeability's Impact
On The
Movement Of Pollution To Ground Water
Thanks to : Brady L.


The purpose of this experiment is to see how different soil permeability’s prevent the   movement of pollutants through them.  My hypothesis is that the outcome of my experiment will show that soils with greater pore space will let more water pass through them.


Science Project - II

Soil contamination by hydrocarbons

Oil absorbing polymers can effectively rehabilitate soil contaminated with motor oil and render the soil suitable for growth. Seeds will geminate in the rehabilitated soil that has been treated with oil absorbing polymers.