1. Chapter 25 Acids & Bases

2. 25.1- Acids, Bases, & pH RWhy is pH important? RThe water we drink has to be tested so it is safe. RWater with a pH that is too high may clog water pipes. RWater with a pH that is too low may corrode the pipes. RWhy is pH important? RThe water we drink has to be tested so it is safe. RWater with a pH that is too high may clog water pipes. RWater with a pH that is too low may corrode the pipes.

3. Acids, Bases, & pH RA solution with a pH value that is less than 7 contains an acid. RA solution with pH values greater than 7 contains a base. RAn acid is a chemical that contributes hydrogen ions, H +, to a solution. RA base is a chemical that contributes hydroxyl ions, OH-, to a solution. RA solution with a pH value that is less than 7 contains an acid. RA solution with pH values greater than 7 contains a base. RAn acid is a chemical that contributes hydrogen ions, H +, to a solution. RA base is a chemical that contributes hydroxyl ions, OH-, to a solution.

4. pH and the pH scale RpH describes the exact concentrations of H+ ions in a solution. RMost instruments that measure pH use a pH scale that runs from 0 to 14. RpH 1 is strongly acidic. RpH 14 is strongly basic. RA solution that has a pH of 7 has equal numbers of H+ and OH- ions & is called a neutral solution. RpH describes the exact concentrations of H+ ions in a solution. RMost instruments that measure pH use a pH scale that runs from 0 to 14. RpH 1 is strongly acidic. RpH 14 is strongly basic. RA solution that has a pH of 7 has equal numbers of H+ and OH- ions & is called a neutral solution.

7. pH and the pH scale RThe more H+ ions there are in a solution, the lower the pH value. RSo… fewer H+ ions in a solution means higher pH value. RAnother way of looking at the scale is to see that as the pH numbers increase, the amount of H+ ions decrease by powers of 10. RThe more H+ ions there are in a solution, the lower the pH value. RSo… fewer H+ ions in a solution means higher pH value. RAnother way of looking at the scale is to see that as the pH numbers increase, the amount of H+ ions decrease by powers of 10.

8. Acid-Base Chemistry RWater plays an important role in acid and base chemistry. RWater is both a weak acid and a weak base. RThe water molecule can split or ionize into H+ and OH- ions. R2H 2 O H 3 O + + OH - RWater plays an important role in acid and base chemistry. RWater is both a weak acid and a weak base. RThe water molecule can split or ionize into H+ and OH- ions. R2H 2 O H 3 O + + OH -

9. Acid-Base Chemistry cont… RThe double-headed arrow in the equation means that water, if left alone, is always in equilibrium with its ions. RWhat does this mean… The rate at which water breaks down into ions is the same as the rate at which the ions re-form into water. RThe double-headed arrow in the equation means that water, if left alone, is always in equilibrium with its ions. RWhat does this mean… The rate at which water breaks down into ions is the same as the rate at which the ions re-form into water.

10. Acid-Base Chemistry cont… RSpecific pH values are needed within your body. RFor your stomach to digest food, Hydrochloric acid (pH of 1.4) is needed to break down the protein molecules in the food. RThese molecules need to be absorbed within your body. RSpecific pH values are needed within your body. RFor your stomach to digest food, Hydrochloric acid (pH of 1.4) is needed to break down the protein molecules in the food. RThese molecules need to be absorbed within your body.

11. Acid-Base Chemistry cont… RReactivity of acids & bases means that these chemicals have many uses. RLye (pH 13) is used to unclog drains. RSulfuric acid (pH 1) is an industrial product, such as cleaning impurities form gasoline. RReactivity of acids & bases means that these chemicals have many uses. RLye (pH 13) is used to unclog drains. RSulfuric acid (pH 1) is an industrial product, such as cleaning impurities form gasoline.

12. Electrolytes & Nonelectrolytes RCurrent is a flow of charge. RWhen a solution contains dissolved ions (charged particles), it can conduct current. RChemicals that conduct current when dissolved in water are called electrolytes. RCurrent is a flow of charge. RWhen a solution contains dissolved ions (charged particles), it can conduct current. RChemicals that conduct current when dissolved in water are called electrolytes.

13. Electrolytes & Nonelectrolytes cont… RAll acids and bases are electrolytes because they contribute ions to a solution. ROther chemicals do not form ions when they are dissolved in solution. Sugar dissolved in water is an example of a non-electrolyte. RAll acids and bases are electrolytes because they contribute ions to a solution. ROther chemicals do not form ions when they are dissolved in solution. Sugar dissolved in water is an example of a non-electrolyte.

14. Common Chemicals Household chemical Acid or Base pH Lemon juiceAcid2 VinegarAcid3 Soda WaterAcid4 Baking sodaBase8.5 Bar soapBase10 AmmoniaBase11

15. pH of Common Substances RTo measure pH, you will use a pH indicator- a chemical that changes color at different pH values.

16. pH and Your Blood RIt is very important that your blood pH stay within the normal range. RYou can regulate the pH of your blood simply by breathing! RIf you hold your breath, more carbon dioxide enters your blood. If you hyperventilate, you blow off carbon dioxide. RIt is very important that your blood pH stay within the normal range. RYou can regulate the pH of your blood simply by breathing! RIf you hold your breath, more carbon dioxide enters your blood. If you hyperventilate, you blow off carbon dioxide.

17. pH and Your Blood cont… RWhen CO2 dissolves, H+ ions are produced in solution. RTherefore, the more CO 2 in your blood, the more acidic your blood will become. RSo… If you breath slowly, the added CO 2 makes your blood more acidic. RWhen you breathe normally, your blood pH ranges between 7.35 and 7.45. RWhen CO2 dissolves, H+ ions are produced in solution. RTherefore, the more CO 2 in your blood, the more acidic your blood will become. RSo… If you breath slowly, the added CO 2 makes your blood more acidic. RWhen you breathe normally, your blood pH ranges between 7.35 and 7.45.

18. 25.2-Acid Rain RRain, snowfall, or any precipitation happens to be naturally acidic. RWhy…this mixes with carbon dioxide and forms small amounts of carbonic acid. RNormal pH of rain is around 5.6 RAny rain, snow, or fog that has a pH lower than 5.6 is called acid rain or acid precipitation. RRain, snowfall, or any precipitation happens to be naturally acidic. RWhy…this mixes with carbon dioxide and forms small amounts of carbonic acid. RNormal pH of rain is around 5.6 RAny rain, snow, or fog that has a pH lower than 5.6 is called acid rain or acid precipitation.

19. Acid Rain cont… RThe chief indicators of acid rain in the atmosphere are the gases sulfur dioxide, sulfur trioxide, nitrogen oxide, and nitrogen dioxide. RMany of these gases are created by industrial processes, traffic, and power plants! RThe chief indicators of acid rain in the atmosphere are the gases sulfur dioxide, sulfur trioxide, nitrogen oxide, and nitrogen dioxide. RMany of these gases are created by industrial processes, traffic, and power plants!

20. THE END!!