Acids and Bases. April 10, Honors Acid and Bases Intro.notebook. Q: What does it mean for a reaction not to go to completion or equilibrium?

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1 Acids and Bases Unit objectives Q: What makes a solution acidic or basic? Q: What about an acid/base makes it acidic/basic? Q: How does and acid/base produce H+/OH In other words: What are the ways in which a reaction can produce H+ or OH Q: How do I quantify the amount of H+/OH in solution? Q: Can you indicate the difference between a strong acid and a weak acid. Q: What does it mean for a reaction not to go to completion or equilibrium? DO: Be able to write Hydrolysis and Ka expressions DO: Calculate the ph of a strong acid. DO: Calculate the ph of a weak acid. Q: What happens when you mix an acid into a base? Q: How do you determine the ph of an unknown acid/base? Q: What is a salt? Q: Can you determine the general acidity of a salt? Q: Can you complete a titration and interpet a titration curve. Apr 3 5:20 AM 1

2 What makes something acidic or basic? Acids all need to be in water (aq) react with metals to form H 2 gas Bases electrolytes electrolytes turn litmus red turn litmus blue caustic ex: vinegar, milk, soda, apples, citrus fruits alkaline (another name) corrosive, caustic ex: ammonia, lye, antacid, baking soda have "H" in 1 st part of formula formula often ends with "OH" (always) produces H 3 O +1 produce OH 1 consumes OH 1 consumes H +1 or H 3 O +1 acids have sour taste Proton (H+) donor Proton (H+) acceptor slippery feel bases have bitter taste Mar 30 9:26 AM 2

3 acid nomenclature: (review) Acids binary (non oxy) oxy acid ide ite ate hydro ic acid ous acid ic acid Hydrogens will balance the overall charge to zero... H +1 PO 4 3 (like ionic) H 3 PO 4 Apr 9 8:13 PM 3

4 What makes something acidic? Anything that can produce H 3 O + ions hydrolysis only (react with water) HX + H 2 O X 1 + H 3 O +1 HCl + H 2 O Cl 1 + H 3 O +1 acids must be aqueous need water to produce hydronium ion What makes something basic? Anything that can produce OH ions hydroysis: X 1 + H 2 O HX + OH 1 F 1 + H 2 O HF + OH 1 ionization: NaOH Na +1 + OH 1 the concentration of H 3 O + and/or concentration of OH 1 determines the ph (measure of acidity) Apr 9 8:19 PM 4

5 Hydrolysis reaction with water acid base HCl + H 2 O H 3 O +1 + Cl 1 H + hydronium ion acidic base acid NH 3 + H 2 O NH OH 1 H + hydroxide basic amphoteric water can act as an acid or a base Mar 30 9:29 AM 5

6 Can OH 1 and H 3 O +1 exist together? auto ionization of water is always happening 2 H 2 O H 3 O +1 + OH 1 in pure water [H 3 O +1 ] = [OH 1 ] = 1 x 10 7 at 25 0 C: brackets mean concentration M M a very small amount ionizes Ionization constant of Water, K w = [H 3 O +1 ] [OH 1 ] = 1 x (10 7 ) (10 7 )=10 14 pure neutral water Apr 9 5:56 AM 6

7 Why is the H + so important? Draw a hydrogen atom: one proton and one electron Draw an hydrogen ion: A Hydrogen ion is just a proton! Apr 4 7:51 AM 7

8 Every acid base reaction is an exchange of an H + (a proton) So each reaction contains an acid and a base. NH H 2 O => NH 3 + H 3 O + Acid H + donor Base H + acceptor Which reactant is the acid? NH 4 + (the one donating H + ) Which reactant is the base? H 2 O (the one accepting the H + ) the presence of H 3 O +1 makes it acidic Apr 3 11:32 AM 8

9 What makes something acidic or basic? amount of: H 3 O +1 hydronium ion (H +1 ) OH 1 hydroxide ion H 3 O +1 vs. OH 1 acidic H 3 O +1 > OH 1 neutral H 3 O +1 = OH 1 basic H 3 O +1 < OH 1 less than 7 = 7 ph scale (0 14) more than 7 NaOH + Na +1 + OH 1 Apr 3 5:21 AM 9

10 CONJUGATE ACIDS and BASES Conjugate: Substance after H + had been donated or accepted ESSENTIALLY SAME ELEMENT/MOLECULE EXCEPT FOR H + Note: Any ACID becomes a conjugate BASE (and VISE VERSA) Pick out the acid, base, and the conjugates. HCl + F Cl + HF CO HI H 2 CO 3 + 2I Apr 3 11:46 AM 10

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