According to About.com, there are many methods to define acids and bases. Svante Arrhenius “acids produce H+ ions and bases produce OH- ions in aqueous solutions.”
Some of the properties of Acids are:
· Sour to taste.
· Changes the color of a litmus paper from blue to red.
· Aqueous solutions of acids are good conductors of electric current i.e., they form electrolytes.
· Acids react with bases to form water and salts.
· Produce H2 gas on reaction with a metal.
Properties of bases are as follows:
· Bitter to taste
· Slippery or soapy to touch and feel
· Bases do not change the color of a litmus paper, they change the color of an acidified red litmus to blue
· Aqueous solutions of bases are also good conductors of electric current and form good electrolytes.
· Bases react with acids to form salts and water.
Various household articles and their response to litmus paper:
Vinegar: is 5% acetic acid and turns a blue litmus paper to red
Lemon juice: is acidic since it also turns a blue litmus paper to red
Soft drinks: Soft drinks convert a blue litmus paper to red indicating their acidic nature (carbonic acid).
Butter milk: Converts a blue litmus paper to red due to the presence of lactic acid.
Milk: Converts a blue litmus paper to red due to lactic acid.
Tap water: If tap water converts blue litmus to red, it indicates that the water is polluted and is acidic. Generally pure water is neutral and does not change the color of a litmus paper.
Cooking oil: It does not change the color of litmus paper thus showing its neutral nature.
Sodium Hydroxide (NaoH): when dissolved in water is basic in nature and converts an acidified red litmus paper to blue.
Household Ammonia when dissolved in water gives a basic solution of Ammonium Hydroxide and thus converts an acidified red litmus paper to blue.
Detergents also convert an acidified red litmus paper to blue indicating their basic nature.
Add two or three spoons of baking soda to some warm water in a wide mouthed bottle and dissolve by shaking. Then add a few drops of dish washer liquid to this solution. Next add vinegar to this liquid solution observing the reaction. A lot of foam is observed.
About: Chemistry. Acids and Bases (2007). Retrieved on March 20, 2007 from: http://chemistry.about.com/library/weekly/blacidbase.htm
About: Chemistry. How To Do a Vinegar & Baking Soda Foam Fight (2007). Retrieved on March 20, 2007 from: http://chemistry.about.com/od/chemistryhowtoguide/ht/foamfight.htm