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Chapter 15. Acids and Bases. Acids. Vocabulary – Hydrogen ion = H +1 = Proton. General Properties of Acids: Acids have a sour taste (ex – citrus fruits, soda, vinegar) Many acids contain hydrogen. Some react with active metals to liberate hydrogen gas (Remember Zn + HCl )
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Chapter 15 Acids and Bases
Acids Vocabulary – Hydrogen ion = H+1 = Proton General Properties of Acids: Acids have a sour taste (ex – citrus fruits, soda, vinegar) Many acids contain hydrogen. Some react with active metals to liberate hydrogen gas (Remember Zn + HCl ) Acids change the color of indicators Acids react with base to produce salt and water HCl + NaOH NaCl + H2O Acids are electrolytes
Acid Definitions An acid may fit one, two or all three definitions Traditional definition (Arrhenius) – Acids contain Hydrogen ion(s) and give them up when in water VIDEO!! H2O HCl (g) ---> H+(aq) + Cl-(aq) VIDEO CLIP!!
Acid Definitions An acid may fit one, two or all three definitions Bronsted definition– Acids are proton DONORS -Similar to Arrhenius definition, but there must be another substance for the acid to give the proton to. HCl (g) + H2O (l) --> H3O+(aq) + Cl-(aq)
Acid Definitions An acid may fit one, two or all three definitions Lewis definition– Acids are electron pair acceptors -The acid might not even have a hydrogen in it + Accepts an e- pair from NH3
Strong Acid: -Ionizes nearly 100% Examples to memorize: -HCl (hydrochloric acid) -H2SO4 (sulfuric acid) when losing the first proton HCl H+ + Cl-
Weak Acid: -Ionizes less than 100% -Lots of the unionized acid will remain Examples to memorize: -HF (hydrofluoric acid) -HCH3COO / CH3COOH (acetic acid) HF H+ + F- REMEMBER – STRONG/ WEAK DOES NOT RELATE TO DANGER LEVEL!!
Classifying Acids Monoprotic – 1 proton to lose ex – HCl (hydrochloric acid) Polyprotic – More than 1 proton to lose Diprotic – 2 protons to lose ex – H2SO4 (sulfuric acid) Triprotic – 3 protons to lose ex – H3PO4 (phosphoric acid)
Acid Structure and Naming Binary Acids – H and one other atom example – HF, HI, HCl Naming – Hydro --- ic acid example – hydrofluoric acid hydroiodic acid hydrochloric acid
Oxyacids – Have oxygen -Come from the eight -ates ION NAMEACID NAME 2 LESS O HYPO – ITE HYPO – OUS ACID 1 LESS O ITE OUS ACID MEMORIZED ATE IC ACID 1 MORE O PER – ATE PER – IC ACID Examples: FROM SULFATE (SO4-2) H2SO2 H2SO3 H2SO4 H2SO5 Hyposulfurous Acid Sulfurous Acid Sulfuric Acid Persulfuric Acid
**Know the acids from sulfate, nitrate, chlorate, phosphate!! Examples – sulfuric, sulfurous, nitric, perchloric, phosphoric, etc. *Some Other Common Acids to Know: Hydrochloric Hydrofluoric Hydroiodic Hydrobromic Acetic
Bases General Properties of Bases: -Bases have a bitter taste (soap, bakers choc) -Dilute aqueous solutions feel slippery (soap) -Bases change the color of indicators -Bases react with acids to produce salts and water HCl + NaOH NaCl + H2O -Bases are electrolytes
Base Definitions A base may fit one, two or all three definitions Traditional definition (Arrhenius) – A base contains Hydroxide ion(s) and gives them up when in water H2O KOH (s) K+(aq) + OH-(aq)
Base Definitions An acid may fit one, two or all three definitions Bronsted definition– Bases are proton ACCEPTORS HCl (g) + H2O (l) H3O+(aq) + Cl-(aq) BASE
Base Definitions An acid may fit one, two or all three definitions Lewis definition– Bases are electron pair donators + Donates an e- pair to the BF3
Neutralization Reactions Stoichiometry of Acid – Base Neutralization Reactions Acid + Base Water + A Salt (an ionic compound) Examples:
Weak Base: -Ionizes less than 100% -Lots of the unionized base will remain Example to memorize: -NH3 (ammonia)
Strong Base: -Ionizes almost 100% Examples to memorize: -Group 1 metal hydroxides (NaOH, KOH, etc.) REMEMBER – STRONG/ WEAK DOES NOT RELATE TO DANGER LEVEL!!
Relative Strength of Acids and Bases HCl + H2O H3O+ + Cl- Conjugate Acid Conjugate Base Acid Base Conjugate – The “leftover” after acid + base combine Conjugate Base – The left over after an ACID loses its Hydrogen ion (take a H away from the acid!) Conjugate Acid – The left over after a BASE gains its Hydrogen ion (add an H to the base!) Another Example: NH3 + H2O NH4+ + OH-
Relative Strength of Acids and Bases Know: Strong Acids: -Hydrochloric -Sulfuric (1st H+ only) Weak Acids: -Hydrofluoric -Acetic
Relative Strength of Acids and Bases Know: Strong Bases: -Metal hydroxides Weak Bases: -Ammonia **The stronger the acid – the weaker the conjugate base** **The stronger the base – the weaker the conjugate acid** Example – Which is the stronger conjugate base – acetate or chloride??
15.4 – Oxides, Hydroxides, Acids Metal oxide + Water Base Ex – Na2O + H2O 2NaOH Nonmetal oxide + Water Acid Ex – SO2 + H2O H2SO3 SO3 + H2O H2SO4
Reactions of Acids and Bases • Acids react with many metals to form Hydrogen gas • Acids react with metal oxides • Acids react with carbonates to form carbon dioxide gas • Hydroxides react with nonmetal oxides • Metal oxides react with nonmetal oxides