Comparative Study of pH of different samples of Products

1. Comparative Study of pH of different samples of Products

2. Introduction to pH pH is a measure of the acidity or basicity of an aqueous solution. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline. Pure water has a pH very close to 7. pH measurements are important in medicine, biology, chemistry, agriculture, forestry, food science, environmental science, oceanography, civil engineering, chemical engineering,nutrition, water treatment & water purification, and many other applications. Mathematically, pH is the negative logarithm of the activity of the (solvated) hydroniumion, more often expressed as the measure of the hydronium ion concentration.

4. Basic Solutions A base is a substance that, in aqueous solution, is slippery to the touch, tastes bitter, changes the colour of indicators (e.g., turns red litmus paper blue), reacts with acids to form salts, and promotes certain chemical reactions. Examples of bases are the hydroxides of the alkali and alkaline earth metals (NaOH, Ca(OH)2, etc). Such substances produce hydroxide ions (OH-) in aqueous solutions, and are thus classified as Arrhenius bases. Bases can be thought of as the chemical opposite of acids. Bases and acids are seen as opposites because the effect of an acid is to increase the hydronium (H3O+) concentration in water, whereas bases reduce this concentration.

5. Acidic solutions An acid is a chemical substance whose aqueous solutions are characterized by a sour taste, the ability to turn blue litmus red, and the ability to react with bases and certain metals (like calcium) to form salts. Aqueous solutions of acids have a pH of less than 7. A lower pH means a higher acidity, and thus a higher concentration of hydrogen ions in the solution. Chemicals or substances having the property of an acid are said to be acidic. Common examples of acids include hydrochloric acid (a solution of hydrogen chloride which is found in gastric acid in the stomach and activates digestive enzymes), acetic acid (vinegaris a dilute solution of this liquid), sulfuric acid (used in car batteries), and tartaric acid (a solid used in baking).

6. Observations : Each group member has measured the pH of around 7 different samples of products and here are the results:

11. Effect of Basicity on our body: • It neutralises the effect of acidity • Eg: Milk of Magnesia • Some with pH higher than 7 like that of tomato are used in making medicine by making use of its leaf. • Some help in preventing cancer of the breast,bladder,colon and rectum,stomach,lung and prostate. • Eg: Green tea,tomato • Prevents bone loss(osteoporosis),dental cavities

12. Effect of Acidity on our body: • Heartburn and Bad breath • Eg: Acetic acid • Too much Acidity can have negative effects such as kidney failure and severe internal burns as once reported from rupture of red blood cells in case of a woman. • Hypokalemia(low potassium levels),hyperreniemia and osteoporosis. • Some are used to treat scurvy(a condition caused by not having enough vitamin c) like Lemon

13. Presentation By : • Areeba Urooj (2927) • Suruchi Trehan (2933) • Yashmi Singh (2953)