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The changes we see around us can be classified into physical and chemical changes. With their individual features and properties, they have different affect on our daily life. Further, their differing properties also has a major role to play in our understanding and knowledge in the field of Chemistry. Let us try to understand more about physical changes, how to identify them and their basic features.
What are Chemical Changes?
A chemical change is one where there are changes in the chemical properties of the components. Their chemical composition may change and the final product may have different properties as compared to the original components.
Let us take the example of an apple. When you cut it and keep it in the open for some time, you will notice that it has a brownish hue on its surface. This happens because the acid in apple reacts with the atmospheric humidity and other trace elements present and gives the apple surface a brownish-yellow color.
Common Examples of Chemical Change
There are quite a few experiments that can be carried out at home or in school laboratories to show chemical changes. Here are some that you can try.
Color Change of Apple
Take a knife and cut an apple in half. Leave it unattended for 10-15 minutes. You will find that the surface of the apple now has a brown-yellow color. This is due to the action of the acid in the apple with the air and moisture around.
Bleaching
Bleaching is a great experiment choice to show that chemical changes can also cause change in colors. Take 200 ml of water in a beaker and add 2 drops of food coloring to it. Mix it thoroughly with a stirring rod until the color is uniformly distributed.
Add about 30 ml bleach into the mixture and in a matter of seconds, you will notice that the color disappears. Though it may seem colorless now, you must remember that this is no longer water, but rather a mixture of water, food color and bleach, which has a different chemical composition from water altogether.
Bottle Balloons
Making balloons from bottles is a great experiment to showcase chemical changes. In a bottle, take water and baking soda. Mix it until the baking soda is completely dissolved. Pour some lemon juice into the bottle and cover the mouth of the bottle with a balloon.
After some time, you will notice that the balloon gets filled with a gas.This is an acid-base neutralization reaction. The base which is baking soda acts with acid in lime juice to produce a gas.
Coke and Mentos
You may already know of this experiment from videos on YouTube. For this experiment, take a small bottle of Coca Cola and put a few Methods pills in it. An explosive reaction will take place in a few seconds as the Coke rushes out of its bottle.
This is a very common experiment, but due to the sudden outburst of energy, one must take certain precautionary steps. Since this is a small-scale experiment, a small bottle of coke and a few Mentos must be used. Using too much can make the experiment spiral out of control, especially if it is carried out at home.
Conclusion
As you see changes around you, you should now be able to understand whether they are chemical or physical changes. Being able to understand them helps a lot in basic Chemistry that forms the backbone of more advanced concepts. Simply looking at changes around you and classifying them as physical or chemical in nature can help you figure out how nature works.
