1 / 67

Acids and Bases

Acids and Bases. BELL WORK. *Obtain ipad from cart corresponding to seat number  answer survey question! PollEv.com/michellemart898. How many foods can you think of that are sour?. sour milk – lactic acid vinegar – acetic acid carbonated beverages – phosphoric acid lemons – citric acid

masonk
Télécharger la présentation

Acids and Bases

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. Acids and Bases

  2. BELL WORK *Obtain ipad from cart corresponding to seat number answer survey question! PollEv.com/michellemart898

  3. How many foods can you think of that are sour? • sour milk – lactic acid • vinegar – acetic acid • carbonated beverages – phosphoric acid • lemons – citric acid • apples – malic acid Chances are almost all the foods you thought of owe their sour taste to an acid!

  4. Question? Who has heard of someone using an antacid for an upset stomach? • What does this indicate about the contents of our stomach? • Answer! Our stomachs contain acid. Medical antacid preparations typically contain weak bases to counteract high levels of acids.

  5. H. pylori

  6. Objectives • List general properties of aqueous acids and bases. • Name common binary acids and oxyacids. • Explain the difference between strong and weak acids and bases.

  7. Acids Characteristics: • sour taste • change color of acid-base indicators • react with bases to produce salts and waters

  8. Acids Characteristics: Acids Conduct Electric Current • Acids dissolve in water break into ions • Ions in solution conduct an electric current • Example: Sulfuric acid in car battery conducts electricity to start car’s engine

  9. Acids Characteristics: • some acids react with active metals and release hydrogen gas

  10. Acid Nomenclature *binary acid- contains only 2 different elements= H + EN element *oxyacid- compound of H,O, and a 3rd element, usually a nonmetal

  11. Name the following acids: 1. HBr • Hydrobromic acid 2. HNO3 • nitric acid 3. H2SO3 • sulfurous acid

  12. Base Characteristics: • bitter taste in aqueous solutions • corrosive/contact skin can result in severe burns • conduct electric current • change color of acid-base indicators • dilute solutions feel slippery • react with acids to produce salts and water

  13. Common Bases • Found in cleaning products • Ammonia is in cleaners and fertilizer • Sodium hydroxide is used to make soap (lye) • Milk of magnesia and antacids

  14. Svante Arrenhius • Swedish chemist 1859-1927 • Understood that aqueous solutions of acids and bases conducted an electric current • Theorized that acids and bases must produce certain ions in solution…

  15. Arrhenius Acids • def. a chemical compound that will increase the concentration of H+ ions in aqueous solutions • HCl  H+ + Cl-

  16. Acids in Water • H+ that separates from the acid and forms with a water molecule H2O to form hydronium ions H3O+

  17. Arrhenius Base • substance that will increase the concentration of hydroxide ions (OH-) in water ex: NaOH NaOH(s) + H20(l)Na+(aq) + OH-(aq) + H2O(l)

  18. Ammonia, NH3 • Base that does not contain an –OH • In water, ammonia attracts an H+ which leaves an OH-.

  19. Strong Acids and Bases • Strong completely ionizes in aqueous solutions • Weak partially ionizes

  20. Section1 Properties of Acids and Bases Chapter 14 Relationship of [H3O+] to [OH–]

  21. HOMEWORK • Section Review pg 476 #1-5

  22. Bell Work • Read the Cross-Disciplinary Connection entitled “Acid Water-A Hidden Menace” on page 477. • Answer the three questions at the end of the article.

  23. List 3 terms that describe this person…

  24. Section2 Acid-Base Theories Chapter 14 Objectives Define and recognizeBrønsted-Lowryacids and bases. Define a Lewis acid and a Lewis base. Name compounds that are acids under the Lewis definition but are not acids under the Brønsted-Lowry definition.

  25. Section2 Acid-Base Theories Chapter 14 Brønsted-Lowry Acids and Bases A Brønsted-Lowry acid is a molecule or ion that is a proton donor. Hydrogen chloride acts as a Brønsted-Lowry acid when it reacts with ammonia. Water can act as a Brønsted-Lowry acid.

  26. Section2 Acid-Base Theories Chapter 14 Brønsted-Lowry Acids and Bases, continued ABrønsted-Lowry baseis a molecule or ion that is a proton acceptor. Ammonia accepts a proton from the hydrochloric acid. It acts as a Brønsted-Lowry base. • The OH− ion produced in solution by Arrhenius hydroxide bases (NaOH) is the Brønsted-Lowry base. • The OH− ion can accept a proton

  27. Section2 Acid-Base Theories Chapter 14 Brønsted-Lowry Acids and Bases, continued In aBrønsted-Lowry acid-base reaction,protons are transferred from one reactant (the acid) to another (the base). acid base

  28. Section2 Acid-Base Theories Monoprotic and Polyprotic Acids • Amonoprotic acidis an acid that can donate only one proton (hydrogen ion) per molecule. • HClO4, HCl, HNO3 only one ionization step

  29. Section2 Acid-Base Theories Chapter 14 Monoprotic and Polyprotic Acids, continued • A polyprotic acid is an acid that can donate more than one proton per molecule. • H2SO4, H3PO4 • Multiple ionization steps • (1) • (2) • Sulfuric acid solutions contain H3O+, ions

  30. Section2 Acid-Base Theories Chapter 14 Monoprotic and Polyprotic Acids, continued • Adiprotic acidis the type of polyprotic acid that can donate two protons per molecule • H2SO4 • A triprotic acid is the type of polyprotic acid that can donate three protons per molecule. • H3PO4

  31. Section2 Acid-Base Theories Chapter 14 Lewis Acids and Bases • ALewis acidis an atom, ion, or molecule that accepts an electron pair to form a covalent bond. • The Lewis definition is the broadest of the three acid definitions. • A bare proton (hydrogen ion) is a Lewis acid

  32. Section2 Acid-Base Theories Chapter 14 Lewis Acids and Bases, continued • The formula for a Lewis acid need not include hydrogen. • The silver ion can be a Lewis acid Any compound in which the central atom has three valence electrons and forms three covalent bonds can react as a Lewis acid.

  33. http://chemwiki.ucdavis.edu/Core/Physical_Chemistry/Acids_and_Bases/Acid/Arrhenius_Concept_of_Acids_and_Baseshttp://chemwiki.ucdavis.edu/Core/Physical_Chemistry/Acids_and_Bases/Acid/Arrhenius_Concept_of_Acids_and_Bases http://chemwiki.ucdavis.edu/Core/Physical_Chemistry/Acids_and_Bases/Acid/Bronsted_Concept_of_Acids_and_Bases • HOMEWORK pg 482 #1-3 answer on same page as section 1 http://chemwiki.ucdavis.edu/Core/Physical_Chemistry/Acids_and_Bases/Acid/Lewis_Concept_of_Acids_and_Bases

  34. Section3 Acid-Base Reactions Chapter 14 Objectives Describe a conjugate acid, a conjugate base, and an amphoteric compound. Explain the process of neutralization. Defineacid rain, give examples of compounds that can cause acid rain, and describe effects of acid rain.

  35. Section3 Acid-Base Reactions Chapter 14 Conjugate Acids and Bases The species that remains after a Brønsted-Lowry acid has given up a proton is the conjugate base of that acid. acid conjugate base

  36. Section3 Acid-Base Reactions Chapter 14 Conjugate Acids and Bases, continued Brønsted-Lowry acid-base reactions involve two acid-base pairs, known a conjugate acid-base pairs. acid1base2 base1acid2

  37. Section3 Acid-Base Reactions Chapter 14 Conjugate Acids and Bases, continued Strength of Conjugate Acids and Bases The stronger an acid is, the weaker its conjugate base The stronger a base is, the weaker its conjugate acid strong acid base acid weak base

  38. Section3 Acid-Base Reactions Chapter 14 Conjugate Acids and Bases, continued Strength of Conjugate Acids and Bases, continued Proton transfer reactions favor the production of the weaker acid and the weaker base. stronger acid stronger base weaker acid weaker base The reaction to the right is more favorable weaker acid weaker base stronger acid stronger base The reaction to the left is more favorable

  39. Section3 Acid-Base Reactions Chapter 14 Relative Strengths of Acids and Bases Relative Strengths of Acids and Bases

  40. Section3 Acid-Base Reactions Chapter 14 Amphoteric Compounds • Any species that can react as either an acid or a base is described asamphoteric. • example:water • water can act as a base • acid1 base2 acid2 base1 • water can act as an acid • base1 acid2 acid1 base2

  41. Section3 Acid-Base Reactions Chapter 14 Amphoteric Compounds, continued –OH in a Molecule The covalently bonded OH group in an acid is referred to as ahydroxyl group. Molecular compounds containing —OH groups can be acidic or amphoteric. The behavior of a compound is affected by the number of oxygen atoms bonded to the atom connected to the —OH group.

  42. Section3 Acid-Base Reactions Chapter 14 Oxyacids of Chlorine

  43. Chapter 14 Neutralization Reactions Strong Acid-Strong Base Neutralization In aqueous solutions,neutralizationis the reaction of hydronium ions and hydroxide ions to form water molecules. Asalt is an ionic compound composed of a cation from a base and an anion from an acid.

  44. Section3 Acid-Base Reactions Chapter 14 Neutralization Reactions

More Related