Presentation Transcript
The Chemistry of Acids and Bases :The Chemistry of Acids and Bases Unit IV
Acid and Bases :Acid and Bases
Acid and Bases :Acid and Bases
Acid and Bases :Acid and Bases
Acids :Acids Have a sour taste. Vinegar is a solution of acetic acid. Citrus
fruits contain citric acid. React with certain metals to produce hydrogen gas. React with carbonates and bicarbonates to produce carbon
dioxide gas Have a bitter taste. Feel slippery. Many soaps contain bases. Bases
Some Properties of Acids :Some Properties of Acids Produce H+ (as H3O+) ions in water (the hydronium ion is a hydrogen ion attached to a water molecule)
Taste sour
Corrode metals
Electrolytes
React with bases to form a salt and water
pH is less than 7
Turns blue litmus paper to red “Blue to Red A-CID”
Some Properties of Bases :Some Properties of Bases Produce OH- ions in water
Taste bitter, chalky
Are electrolytes
Feel soapy, slippery
React with acids to form salts and water
pH greater than 7
Turns red litmus paper to blue “Basic Blue”
Some Common Bases :Some Common Bases NaOH sodium hydroxide lye
KOH potassium hydroxide liquid soap
Ba(OH)2 barium hydroxide stabilizer for plastics
Mg(OH)2 magnesium hydroxide “MOM” Milk of magnesia
Al(OH)3 aluminum hydroxide Maalox (antacid)
Acid/Base definitions :Acid/Base definitions Definition #1: Arrhenius (traditional)
Acids – produce H+ ions (or hydronium ions H3O+)
Bases – produce OH- ions
(problem: some bases don’t have hydroxide ions!)
Slide 10:Arrhenius acid is a substance that produces H+ (H3O+) in water Arrhenius base is a substance that produces OH- in water
Acid/Base Definitions :Acid/Base Definitions Definition #2: Brønsted – Lowry
Acids – proton donor
Bases – proton acceptor
A “proton” is really just a hydrogen atom that has lost it’s electron!
Slide 12:A Brønsted-Lowry acid is a proton donor
A Brønsted-Lowry base is a proton acceptor acid conjugate base base conjugate acid
ACID-BASE THEORIES :ACID-BASE THEORIES The Brønsted definition means NH3 is a BASE in water — and water is itself an ACID
Conjugate Pairs :Conjugate Pairs
Learning Check! :Learning Check! Label the acid, base, conjugate acid, and conjugate base in each reaction: HCl + OH- ? Cl- + H2O H2O + H2SO4 ? HSO4- + H3O+