Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Acids and bases


Published on

Acids and Bases Form 4

Published in: Education
  • awsome
    Are you sure you want to  Yes  No
    Your message goes here

Acids and bases

  1. 1. Chapter 7ACIDS AND BASES<br />
  2. 2. What is acid?<br /><ul><li>a substance that ionizes in water to produce hydrogen ions, H+</li></ul>What is base?<br /><ul><li>a substance that reacts with an acid to </li></ul> form only salt and water<br />What is alkali?<br /><ul><li>Soluble bases that produce OH¯ ions in water</li></li></ul><li>Chemical properties of acid<br /><ul><li> Sour taste
  3. 3. pH less than 7
  4. 4. Corrosive
  5. 5. Conduct electricity
  6. 6. Acid can react with</li></ul> a) bases to produce salts and water<br /> b) metals to produce salts and hydrogen gas<br /> c) carbonates to produce salts , carbon dioxide gas and water<br />
  7. 7. Chemical properties of base<br /><ul><li> Bitter/smooth/soapy
  8. 8. pH more than 7
  9. 9. Corrosive
  10. 10. Conduct electricity
  11. 11. Base can react with</li></ul> a)Acid to produce a salt and water<br /> b)Heated with ammonium salt to produce ammonia gas<br />video <br />
  12. 12. Uses of acids in daily life<br /><ul><li>Sulphuric acid – paints, detegents, polymers, fertilisers
  13. 13. Carbonic acid- make carbonated drinks
  14. 14. Ethanoic acid- vinegar</li></ul>Uses of base in daily life<br /><ul><li>Sodium hydroxide – soaps, detergents, bleaching agents
  15. 15. Magnesium hydroxide – toothpaste
  16. 16. Ammonia- fertilisers</li></li></ul><li>Role of water in the formation of hydrogen ions<br /><ul><li>In the presence of water, an acid will ionize to form the hydrogen ions, H+
  17. 17. So, water is essential for the formation of hydrogen ions that cause acidity</li></li></ul><li>Role of water in the formation of hydroxide ions<br /><ul><li>In the presence of water, alkali will dissociate to form hydroxide ions, OH¯
  18. 18. Hence, water is essential for the formation of hydroxide ions that cause alkalinity</li></li></ul><li>pH scale<br />
  19. 19. <ul><li>A set of numbers used to show the degree of acidity and alkalinity of a solution
  20. 20. pH values of less than 7 indicates an acidic solution
  21. 21. pH values of more than 7 indicates an alkaline solution
  22. 22. pH values of 7 indicates a neutral solution</li></li></ul><li>pH values<br />Higher pH value <br /><ul><li>more alkaline
  23. 23. higher concentration of hydroxide ion</li></ul>Lower pH value <br /><ul><li>more acidic
  24. 24. higher concentration of hydrogen ion</li></ul>When acids meets base<br />
  25. 25. pH is actually a measurement of the concentration of hydrogen, H+ in a solution<br />The higher the concentration of the H+<br /> ions, the lower the pH value, and more acidic the solution is<br />The higher the concentration of the OH¯ ions, the higher the pH value and the more alkaline solution the solution is.<br />
  26. 26. Acid<br /><ul><li>Strong acidis an acid that dissociate (ionize ) completely in water to form hydrogen ion,H+ of high concentration
  27. 27. Weak acidis an acid that dissociate (ionize ) partially in water to produce hydrogen ions,H+ of low concentration.</li></li></ul><li>Mineral acids such as hydrochloric acid, nitric acid, and sulphuric acid are strong acids<br />Weak acids-ethanoic acid, methanoic acid, citric acid, tartaric acid<br />
  28. 28. Alkali<br /><ul><li>Strong alkaliis produce when a base dissociates completely in water to produce hydroxide ions, OH- of high concentration
  29. 29. Weak alkaliis produced when a base dissociates partially to produce hydroxide ions, OH- of low concentration.</li></li></ul><li>Strong alkali- sodium hydroxide, potassium hydroxide<br />Weak alkali- ammonia solution<br />
  30. 30. EDITED BY :<br />NoorLailibintiMohamad Elias<br />D20091034948<br />ISMP KIMIA 2009/2010<br />Thank you<br />