DO NOW: 1 2. CATALYST ACTIVITY: 1. What are acids and bases? 2. Using Table K, what do acids have in common?

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1 Name: Period: Date: Hybrid Chemistry Regents Prep Ms. Hart/Mr. Kuhnau Unit 8: ACID BASE CHEMISTRY Lesson 1: Acids/Bases and ph By the end of today, you will have an answer to: What are acids and bases and how does the ph scale tell us how acidic or basic a solution is? DO NOW: CATALYST ACTIVITY: 1. What are acids and bases? 2. Using Table K, what do acids have in common? 3. Using Table L, what do bases have in common?

2 ACIDS BASES Common properties Arrhenius Definition KEY WORDS ph value Hydrogen ion (H + ) Hydronium ion (H 3O + ) Hydroxide ion (OH ) What happens when dissolved in water? Reference Table Examples Alternate Theory (Brønsted-Lowry) How do we measure the strength of an acid or base? ph scale: ph is a measure of the concentration of H + ions or OH - ions in a solution. Concentration same as Molarity, so ph is also dependent on the molarity of a solution. What is the meaning of neutral?

3 ACID BASE NEUTRAL Fill in the blanks in the table below. Acid, Base, or Neutral? Possible ph a. 4 b. Neutral c. 8 d. Base EVERY ph represents a log scale and thus the hydroxide concentration increases x10 every time you move one ph value. Example 1: ph of 1 versus ph of 2 Example 2: If a solution starts at a ph of 10 and becomes 100 more acidic, what is the new ph of this solution? PARTNER PRACTICE: Example 3: ph of 8 versus ph of 9 Example 4: If a solution starts at a ph of 6 and becomes 100 more acidic, what is the new ph of this solution? Example 5: If a solution starts at a ph of 10 and becomes 100 more basic, what is the new ph of this solution? Challenge: The ph of the pond water was 8.0 before the spill. After the spill, the pond water is 1,000 times more acidic. What is the new ph of the pond water after the spill?

4 Name: Pd: Date: KIPP NYC College Prep Chem Regents Prep 8.1 WORK: ACID/BASE DAY 1 15 points Directions: Answer the following questions. 1. Which substance is an Arrhenius base? Explain why in the lines provided below. (1) CH 3OH (2) CH 3Cl (3) LiOH (4) LiCl 2. The compound NaOH (s) dissolves in water to yield (1) hydroxide ions as the only negative ions (2) hydroxide ions as the only positive ions (3) hydronium ions as the only negative ions (4) hydronium ions as the only positive ions 3. An Arrhenius acid has (1) only hydroxide ions in solution (2) only hydrogen ions in solution (3) hydrogen ions as the only positive ions in solution (4) hydrogen ions as the only negative ions in solution 4. Which Lewis electron-dot diagram correctly represents a hydroxide ion? 6. Which statement describes an alternate theory of acids and bases? (1) Acids and bases are both H + acceptors (2) Acids and bases are both H + donors. (3) Acids are H + acceptors, and bases are H + donors. (4) Acids are H + donors, and bases are H + acceptors. 7. The only positive ion found in H 2SO 4 (aq) is the (1) ammonium ion (2) hydronium ion (3) hydroxide ion (4) sulfate ion 8. Which two formulas represent Arrhenius acids? (1) CH 3COOH and CH 3CH 2OH (2) HC 2H 3O 2 and H 3PO 4 (3) KHCO 3 and KHSO 4 (4) NaSCN and Na 2S 2O 3 9. Which compound releases hydroxide ions in an aqueous solution? (1) CH 3COOH (2) HCl (3) CH 3OH (4) KOH 10. A hydrogen ion, H+, in aqueous solution may also be written as (1) H 2O (2) H 3O + (3) H 2O 2 (4) OH As the ph of a solution is changed from 3 to 6, the concentration of hydronium ions (1) increases by a factor of 3 (2) increases by a factor of 1000 (3) decreases by a factor of 3 (4) decreases by a factor of Which ion is the only negative ion produced by an Arrhenius base in water? (1) NO 3 - (2) Cl - (3) OH - (4) H -

5 I can give you a six-word formula for success: Think things through then follow through. Sir Walter Scott 12. Solution A has a ph of 3 and solution Z has a ph of 6. How many times greater is the hydronium ion concentration in solution A than the hydronium ion concentration in solution Z? (1) 100 (2) 3 (3) 2 (4) Which statement correctly describes a solution with a ph of 9? (1) It has a higher concentration of H 3O + than OH - (2) It has a higher concentration of OH - than H 3O + (3) It has the same concentration of H 3O + as of OH - Part II: Free Response 14. Three bottles of liquids labeled 1, 2, and 3 were found in a storeroom. One of the liquids is known to be drain cleaner. Drain cleaners commonly contain KOH or NaOH, both strong bases. The ph of each liquid at 25 C was determined with a ph meter. The table below shows the test results. Explain how the ph results in this table enable a student to correctly conclude that bottle 3 contains the drain cleaner. 15. A truck carrying concentrated nitric acid overturns and spills its contents. The acid drains into a nearby pond. The ph of the pond water was 8.0 before the spill. After the spill, the pond water is 1,000 times more acidic. What is the new ph of the pond water after the spill?