Acids bases and salts


Published on

A mixed media lesson on Acids and bases

Published in: Business, Technology
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Acids bases and salts

  1. 1. Acids Bases and Salts A video lesson
  2. 2. Introduction
  3. 3. Introduction <ul><li>Ascorbic acid is better known as .. </li></ul><ul><li>When dissolved in water, what taste do acids have? Sour, tart </li></ul><ul><li>What kind of taste do bases have? </li></ul><ul><li>Vitamin C </li></ul><ul><li>Sour, tart </li></ul><ul><li>Bitter </li></ul>
  4. 4. Introduction <ul><li>What kind of feel do acids have? </li></ul><ul><li>What kind of feel do bases have? </li></ul><ul><li>Acids and bases are both electrolytes. What does this mean? </li></ul><ul><li>Like water, sting </li></ul><ul><li>Slippery </li></ul><ul><li>Good conductors of electric current </li></ul>
  5. 5. Introduction <ul><li>How do acids react with metals? </li></ul><ul><li>How do bases react with metals? </li></ul><ul><li>What is a good way of testing if a liquid is an acid or base? </li></ul><ul><li>Vigorously </li></ul><ul><li>They don’t </li></ul><ul><li>pH indicator (litmus) paper </li></ul>
  6. 6. Arrhenius Acids and Bases <ul><li>What is the process that occurs when acids and bases are mixed? </li></ul><ul><li>What is produced when an acid and base are mixed? </li></ul><ul><li>What happens to the HCl molecule in water? </li></ul><ul><li>Neutralization </li></ul><ul><li>Water and a salt (ionic compound) </li></ul><ul><li>It dissociates into ions </li></ul>
  7. 7. Arrhenius Acids and Bases <ul><li>The positively charged H + ion is called a CATION and the negatively charged Cl - ion is called an ANION. </li></ul><ul><li>The hydrogen ion is just a PROTON </li></ul>
  8. 8. Arrhenius Acids and Bases <ul><li>When a base is dissolved in water, it releases an OH - ion. </li></ul><ul><li>Arrhenius defined acids as substances that release H + ions when dissolved in water… </li></ul><ul><li>…and bases are substances that generate OH - ions when dissolved in water. </li></ul>
  9. 9. Arrhenius Acids and Bases <ul><li>What is produced when the H+ from an acid is mixed with an OH- from a base? </li></ul><ul><li>H 2 O WATER </li></ul><ul><li>Acid + Base  WATER + SALT </li></ul>
  10. 10. Bronstead-Lowry Acids and Bases <ul><li>Arrhenius’ definition could not explain why BAKING SODA is a base. </li></ul><ul><li>According to Bronstead-Lowry </li></ul><ul><ul><li>An acid is anything that DONATES a proton </li></ul></ul><ul><ul><li>A base is anything that ACCEPTS a proton. </li></ul></ul><ul><ul><li>Both acids and bases are related to the concentration of H + . </li></ul></ul>
  11. 11. Bronstead-Lowry Acids and Bases <ul><li>Acids INCREASE H + concentration, while bases DECREASE H + concentration. </li></ul><ul><li>The acidity or basicity of something can be measured by its PROTON concentration. </li></ul>
  12. 12. Strong and weak acids and bases <ul><li>A strong acid READILY TRANSFERS H+ ions to water. </li></ul><ul><li>The more COMPLETE the transfer of H+ ions, the STRONGER the acid. </li></ul>
  13. 13. Strong and weak acids and bases <ul><li>Why is vinegar a weak acid? </li></ul><ul><ul><li>It does not readily transfer its ions to water </li></ul></ul>
  14. 14. Conjugate Acid-Base Pairs <ul><li>Conjugate acid-base pairs differ by only ONE PROTON. </li></ul><ul><li>There is an INVERSE relationship between the strength of an acid or base and its conjugate base or acid. </li></ul><ul><ul><li>The STRONGER the acid, the WEAKER its conjugate base. </li></ul></ul><ul><ul><li>The STRONGER the base, the WEAKER its conjugate acid. </li></ul></ul>
  15. 15. The pH scale <ul><li>In pure water, the amount of H 3 O + ions is 10 -7 moles/liter. </li></ul><ul><li>What is the name of the scale that is used to measure acidity or basicity? </li></ul><ul><ul><li>The pH scale </li></ul></ul><ul><li>Where are acids on the scale? <7 </li></ul><ul><li>Where are bases on the scale? >7 </li></ul>
  16. 16. The pH in the chemistry of nature <ul><li>Rainfall with a pH below 5.6 is called acid rain. </li></ul><ul><li>Human blood must have a pH between 7.35 and 7.45. </li></ul><ul><li>Buffers resist changes in pH level. </li></ul>
  17. 17. Video Quiz