1. Chapter 7 Acids & Bases

2. About Acids… Sour taste Neutralize base Dissolves active metal Litmus indicator = red Definitions –Arrhenius: form H + in water –Bronsted-Lowry: donates a proton

3. About Bases… Bitter taste Neutralize acid Feels slippery or “soapy” Litmus indicator = blue Definitions –Arrhenius: form OH - in water –Bronsted-Lowry: accepts a proton

4. Strong Acids & Bases Come apart completely in water –Examples: Hydrochloric acid, sulfuric acid, nitric acid

5. Weak Acids & Bases Come apart only partially in water –Examples: acetic acid, carbonic acid, hydrocyanic acid

6. Acids and Bases

7. Acid/Base Neutralization (Titration) Strong acid + strong base HCl + NaOH  H 2 O + NaCl NaCl H + Cl - Na + OH - H 2 O

9. pH Calculations pH = – log [H + ] [H + ] = 10 -pH What is the pH of a solution that has a hydrogen ion concentration of 8.5 x 10 -4 M? If a solution has a pH of 9.4, what is the hydrogen ion concentration?

10. Acids & You Acid rain Source: http://www.newint.org/issue114/rain.htm

12. Acids & You Digestion Source: http://www.solvaypharma.ca/en/areas/gastro2.asp ~ 2 liters of stomach acid per day!

13. Acids & You In your car Source: http://newark.rutgers.edu/~huskey/images/lead-acid-battery.gif

14. Bases & You Cleaning –Clarifying shampoos Higher pH than the hair itself makes the hair shaft swell and allows cleaning agents to penetrate more deeply –Detergents Break up oil and grease –Drain cleaner Very high pH to eat through acidic hair & skin debris

15. Bases & You Antacids –Acid-base neutralization –Calcium carbonate + stomach acid

16. Bases & You Baking –Baking soda & baking powder react with acid in the batter to form bubbles of CO 2 Source: http://www.joyofbaking.com/bakingsoda.html

17. Practice Nitric acid (HNO 3 ) reacts with magnesium hydroxide in an acid-base neutralization reaction. –Write the balanced equation. –Name both products in the reaction. 2HNO 3 + Mg(OH) 2  2H 2 O + Mg(NO 3 ) 2 Water and magnesium nitrate

18. Practice What is the molarity? –50.0g of potassium bromate dissolved in enough water to make 1.5L of solution (2 decimal places) How many grams to weigh out? –Make 1.8L of a 0.75M solution of calcium perchlorate (2 decimal places) 0.2M 322.52g

19. Practice What is the percent concentration? (1 decimal place) –45mL of ethanol dissolved in 1L of water –85g of NaCl dissolved in 315g of water 4.5% v/v 21.3% m/m

20. Practice How many times more acidic is lemon juice (pH 1.5) than blood (pH 7.5)? Something that is 10,000 times more basic than tomatoes (pH 4.2) would have a pH of what? 1,000,000 or 10 6 times more acidic pH of 8.2

21. Practice What is the pH? (2 decimal places) –[H + ] = 1.87 x 10 -4 M What is the hydrogen ion concentration? –pH = 11.45 3.73 3.55 x 10 -12 M