Acids and Bases Chapters 14 and 15
Properties of Acids/Bases • Acids • Sour Taste • Change the color of an acid-base indicator • React with metals to form H2 gas • React with bases to produce salts and water • Conduct electric current. • Bases • Taste Bitter • Change the color of an acid-base indicator • Feel Slippery • React with acids to produce salts and water • Conduct electric current
Examples of Common Acids/Bases • Acids • Citric Acid (fruits) • Acetic Acid (vinegar) • Sulfuric Acid • Nitric Acid • Phosphoric Acid • Hydrochloric Acid • Bases • Ammonia • Milk • General Cleaning (NaOH) • Soaps
Naming Acids • Binary Acids- acid that contains only two different elements. Hydrogen and one more • Hydro____ic acid • HCl= hydrochloric acid • HBr= hydrobromic acid
Naming Acids • Oxyacid-an acid that is a compound of hydrogen, oxygen, and a third element • Look on your reaction foldable or your naming charts. • We wrote this information down back in October.
Arrhenius Acids and Bases • Arrhenius Acid- a chemical compound that increases the concentration of the hydrogen ions, H+, in aqueous solutions. • Form H3O+ • Arrhenius Base- a substance that increases that the concentration of hydroxide ions, OH-, in aqueous solutions
Strength of Acids • Strong: ionize 100% in water • Only 7 are Strong • All are strong electrolytes • HI, HClO4, HBr, HCl, HClO3, H2SO4, HNO3 • Weak Acid: doesn’t ionize 100% in water • All of the other acids
Strength of Bases • Strong Bases: dissociates 100% • Only 8 • Strong electrolytes • Ca(OH)2, Sr(OH)2, Ba(OH)2, NaOH, KOH, RbOH, CsOH, LiOH • Weak Bases: doesn’t dissociate 100% • All of the others
Homework • Page 491 Numbers 3, 5, 8-11 • On 8-11 Name and Classify as strong/weak
Acid/Base Theories • Bronsted-Lowry Acid- a molecule or ion that is a proton donor • Bronsted-Lowry Base- a molecule or ion that is a proton acceptor • Water can act as both an acid and a base
Bronsted-Lowry • Conjugate Acid/Base Pairs • Acid to form conjugate base it looses an H • Base to form conjugate acid it gains an H • Amphoteric-species that can react as either an acid or a base
Bronsted-Lowry • Monoprotic Acid- an acid that can donate only one H+ • Polyporitc acid is an acid that can donate more than one H+ over a series of steps.
Strong Acid-Base Neutralization Reactions • Strong Acid + Strong Base = Salt + water • Look on page 492 Number 26
Concept of pH • When water self ionizes it forms an equilibrium reaction. • K is a constant that represents equilibrium • Kw= ionization constant of water • Kw= 1.0 X 10-14 • Kw=[H3O+][OH-] AKA: Ka and Kb
The pH Scale • pH 0-14 This is based on powers of 10 • <7 acid • >7 base • =7 neutral
Formulas • pH + pOH=14 • pH= -log [H3O+] • [H3O+]=10-pH • pOH= -log [OH-] • [OH-]= 10-pOH • Kw= [H3O+] [OH-]
Examples • Determine the hydronium and hydroxide ion concentration in a solution that is 1E-4M HCl. • 1E-3M HNO3 • 3.0E-2M NaOH • 1.0 E-4 M Ca(OH)2
Examples • Determine the pH of the following species • 1.0 E-3M HCl • 1.0 E-5 M HNO3 • 1.0 E-4 M NaOH • 1.0 E-2 M KOH • Show all ways to work these
Examples • The pH of a solution is 5. What is the concentration of the hydronium ion? • The pH of the solution is 12. What is the hydronium ion concentration? • The pH is 1.5. Calculate the hydronium and hydroxide ion. • The pH is 3.67 determine the hydronium and hydroxide ion.
Homework • Page 523 Numbers 8-15, 16 a,b
Determining pH and Titrations • Acid-Base indicators: compounds whose colors are sensitive to pH • Common indicators: methyl red, bromthymol blue, methyl orange, bromphenol blue, phenolphthalein, phenol red
Determining pH and Titrations • You can also use pH paper or a pH meter to give the pH of the solution without a color change. • Talk about Titrations
