Acids, Bases and Neutralization
- 2. INDEX S.No. Description Slide No. 1. Acids 3-7 2. Bases 8-11 3. Acids vs Bases 12 4. Determining Acids and Bases 13 5. Neutralization 14-16 6. Sources 17
- 5. Strong Acids Weak Acids Sources Hydrochloric Acid (HCl) Acetic Acid (HC2H3O2) Vinegar Nitric Acid (HNO3) Formic Acid Ant’s sting Sulphuric Acid (H2SO4) Citric Acid Citrus fruits such as oranges, lemons etc. Phosphoric Acid (H3PO4) Lactic Acid Curd
- 7. •Sulphuric acid is used in the manufacture of fertilizers(like ammonium sulphate), paints, dyes, chemicals, plastics, synthetic fibers, detergents, explosives and car batteries. •Nitric acid is used for making fertilizers(like ammonium nitrate),explosives(like TNT (Tri-Nitro-Toluene),dyes and plastics. •Dilute hydrochloric acid is used for removing oxide film from steel pipes before they are given a coating of zinc (or galvanized). It is also used for removing the deposit from inside the boilers. This process is called de- scaling of boilers. Hydrochloric acid is also used in dyestuff, textile, food and leather industries. Hydrochloric Acid found in the stomach is used for digestion of food. Phosphoric acid is used in flavorings. DNA or Deoxyribonucleic acid is present in the nucleus of living cells. It carries the genetic information and controls every feature of the living organism such as the looks, the color of eyes and height. •Fats and oils contain complex compounds called fatty acids. •Proteins contain Amino Acid.
- 8. •pH greater than 7. •Neutralizes acids. •Bitter in taste and soapy to touch. •Forms OH -ions in solution. •Turn red litmus blue. Bases which are soluble in water are called Alkalies. Strong bases are also poisonous and corrosive to skin. STRONG BASES WEAK BASES Sodium Hydroxide (NaOH) Calcium Hydroxide {Ca(OH2)} Lithium Hydroxide (LiOH) Ammonium Hydroxide (Nh4OH) Potassium Hydroxide (KOH) Magnesium Hydroxide {Mg(OH2)}
- 9. REACTION WITH DIFFERENT COMPOUNDS • Alkalis react with acids to form salt and water. 2NaOH + H2So4 = Na2SO4 + 2H2O • Alkalis react with carbon-dioxide to form carbonates. Ca(OH)2 + CO2 = CaCO3 + H2O
- 10. pH of Common Substances pH stands for “potential hydrogen” and is a measure of how many H+ ions there are in a solution and as such is a measure of the acidity or basicity of a solution. The more H+ ions are, the lower the pH will be.
- 11. •Sodium Hydroxide (Caustic Soda) is used in the manufacture of soap. It is used in petroleum-refining in making medicines, paper, pulp, etc. It is used in making rayon. •Calcium hydroxide is also known as slaked lime. It is used to neutralize acid in water supplies; in the manufacture of bleaching powder; as a dressing material for acid burns; as an antidote for food poisoning; in the preparation of fungicides and in the mixture of whitewash. It is mixed with sand and water to make mortar which is used in the construction of buildings. It is also used by farmers on the fields to neutralize the harmful effects of acid rain. •Ammonium hydroxide is used to remove ink spots from clothes and to remove grease from window panes. It is used in the cosmetic industry. •Alkalis are used in alkaline batteries. Generally potassium hydroxide is used in such batteries. •Magnesium hydroxide(also called milk of magnesia) is a laxative and an antacid. •Aluminum hydroxide is used to manufacture other aluminum compound and to make gastric medicine(antacid). •Sodium carbonate is used as a washing soda for washing clothes. It is also used for softening hard water. •Sodium hydrogen carbonate is used as baking soda in cooking food and in making various baking powders. It is also used as an antacid to neutralize stomach acidity.
- 12. BASERelated to H+ (proton) concentration ACID pH < 7 Sour taste React with metals pH > 7 Bitter taste Doesn’t react with metals Affects pH and litmus paper pH + pOH = 14 DIFFERENT ALIKE DIFFERENT
- 13. • Litmus paper • pH • Red Cabbage Juice • Turmeric • China rose INDICATORS are substances that change colour depending on whether the solution is acid or alkaline. Some indicators are more useful than others
- 14. NEUTRALIZATION • The process of treating an acid with a base (or an alkali) to form salt and water with the evolution of heat is called neutralization. NaOH + HCl = NaCl + H2O Sodium Hydroxide Hydrochloric Acid Sodium Chloride Water (Base) (Acid) (Salt) • When the solution of acid and alkali are mixed in equal amounts, the resulting solution is neither acidic nor alkaline (neutral solution)with a pH of 7. The new substance formed is called a salt.
- 15. NEUTRALIZATION IN EVERY DAY LIFE INDIGESTION • Hydrochloric acid in the stomach helps to digest food. But too much acid causes indigestion. To relieve indigestion, we take an antacid such as milk of magnesia, which contains magnesium hydroxide. It neutralizes the effect of excessive acid. ANT BITE • When an ant bites, it injects the acidic liquid(formic acid)into the skin. The effect of the acid can be neutralized by rubbing moist baking soda(sodium hydrogen carbonate)or calamine solution, which contains zinc carbonate.
- 16. • Excessive use of chemical fertilizers makes the soil acidic. Plants do not grow well when the soil is either too acidic or too basic. When the soil is too acidic, it is treated with bases like quick lime(calcium oxide)r slaked lime(calcium hydroxide).If the soil is basic, organic matter is added to it. Organic matter releases acids which neutralizes the basic nature of the soil. TOOTH DECAY • Tooth enamel is made up of calcium phosphate, which is the hardest substance present in the body. The bacteria present in the mouth act on sugars to produce acids which corrode(soften) the enamel. This can be prevented by brushing the teeth using toothpastes which are basic or alkaline. Toothpaste neutralizes excess of acid and thus prevent tooth decay. SOIL TREATMENT
- 17. SOURCES • Google • Wikipedia • Science NCERT Class 7 Book • Awareness Science for seventh Class; Lakhmir Singh, Manjit Kaur • Visualised Science and Technology