1 / 18

Chapter 25

Chapter 25. Lesson 1. Acids. Although some acids can burn and are dangerous to handle, most acids in foods are safe to eat. What acids have in common, however, is that they contain at least one hydrogen atom that can be removed when the acid is dissolved in water. Acids.

leo-pace
Download Presentation

Chapter 25

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 25 Lesson 1

  2. Acids • Although some acids can burn and are dangerous to handle, most acids in foods are safe to eat. • What acids have in common, however, is that they contain at least one hydrogen atom that can be removed when the acid is dissolved in water.

  3. Acids • An acid is a substance that produces hydrogen ions H+ in a water solution. It is the ability to produce these ions that gives acids their characteristic properties • When an acid dissolves in water, H+ ions interact with water molecules to form H3O+ ions, which are called hydronium ions.

  4. Definitions • Acids • Ionize to form hydronium ions (H3O+) in water HCl + H2O  H3O+ + Cl–

  5. Dissociation of Acids • When hydrogen chloride (HCl) dissolves in water, a hydronium ion and a chloride ion are produced.

  6. Common Acids • At least four acids (sulfuric, phosphoric, nitric, and hydrochloric) play vital roles in industrial applications.

  7. Bases • Any substance that forms hydroxide ions, OH, in a water solution is a base. • In addition, a base is any substance that accepts H+ from acids. • They are the opposite of acids.

  8. Definitions • Bases • Dissociate or ionize to form hydroxide ions (OH-) in water NH3 + H2O  NH4+ + OH-

  9. Dissociation of Bases • The base dissociates into a positive ion and a negative iona hydroxide ion (OH).

  10. Dissociation of Bases • Unlike acid dissociation, water molecules do not combine with the ions formed from the base.

  11. Ammonia • Ammonia is a base that does not contain –OH. • In a water solution dissociation takes place when the ammonia molecule attracts a hydrogen ion from a water molecule, forming an ammonium ion (NH4+). This leaves a hydroxide ion (OH).

  12. Common Bases • You probably are familiar with many common bases because they are found in cleaning products used in the home.

  13. Common Bases • Some drain cleaners contain NaOH, which dissolves grease, and small pieces of aluminum. • The aluminum reacts with NaOH, producing hydrogen and dislodging solids, such as hair.

  14. Definitions • Indicator • Organic substance that changes color in an acid or base • Examples: • litmus - red/blue • phenolphthalein - colorless/pink • goldenrod - yellow/red • red cabbage juice - pink/green

  15. sour taste corrosive electrolytes turn litmus red react with metals to form H2 gas bitter taste corrosive electrolytes turn litmus blue slippery feel Properties ACIDS BASES

  16. H3PO4 - soft drinks, fertilizer, detergents H2SO4 - fertilizer, car batteries HCl - gastric juice HC2H3O2 - vinegar Uses ACIDS

  17. NaOH - lye, drain and oven cleaner Mg(OH)2 - laxative, antacid NH3 - cleaners, fertilizer Uses BASES

More Related