Review of Acids, Bases, & Salts

Has H in the formula Produces H+ as the only positive ion in solution Arrhenius Acid

Inorganic – formula starts with H Organic – formula ends with COOH Formula of an Acid

Properties of Acids Sour Taste Electrolytes React with bases to form a salt + H2O Turn litmus RED React with most metals to produce H2(g) Properties of Acids

HCl  H+ + Cl- or HCl + H2O  H3O+ + Cl- Ionization of an Acid

Arrhenius Base Has OH in the formula Produces OH- as the only negative ion in solution Arrhenius Base

Has format MOH M is a metal Formula of a Base

Properties of Bases Bitter Taste Slippery Feel Electrolytes React with acids to form a salt + H2O Turn litmus BLUE Properties of Bases

NaOH  Na+ + OH- Ionization of a Base

NH3 + H2O  NH4+ + OH- Ionization of NH3

Metal + Nonmetal Formula of a Salt

Write the formula of potasium sulfate K+ & (SO4)2- K2SO4 Write the formula of potasium sulfate

Electrolytes Solutions conduct – they contain ions Acids (HX), bases (MOH), & salts (MX) are electrolytes Electrolytes

Solutions of covalent compounds (all nonmetals). They do NOT conduct. NONelectrolytes

Identify the electrolytes Yes - B Yes - B LiOH CH3COOH C6H12O6 NaNO3 H2SO4 CH3OH Ca(OH)2 HCl C8H18 Al(OH)3 HNO3 CH3CH2COOH K2SO4 CH3CHOHCH3 CH3OCH3 H3PO4 Mg(OH)2 CH3CH2OH Yes - A Yes - A Yes - A No Yes - S Yes - S Yes - A No No No Yes - A Yes - B Yes - A Yes - B No No

0-14 Acidic: 0 to 7, Neutral: 7 Basic: 7-14 pH scale

pH = 0 Most acidic on pH scale

pH = 14 Most basic on pH scale

Hydroxide ion OH-

Hydrogen ion H+

Hydronium ion. Interchangeable with H+. H3O+

[H+]  [OH-] Acidic Solution

[OH-]  [H+] Basic Solution

If the pH changes from 3 to 5, how does the [H+] change? The pH changes by 2, so the [H+] changes by 102 or 100X. Since the pH went up, it became LESS acidic. The new solution has a [H+] 100 times less than the original solution. If the pH changes from 3 to 5, how does the [H+] change?

How can pH be safely tested? Instrumental – use pH meter Indicators – use a series of indicators to narrow down the pH range Test acids with metals (NOT Cu, Ag, or Au) How can pH be safely tested?

Proton Donor Bronsted-Lowry Acid

Proton Acceptor Bronsted-Lowry Base

Bronsted-Lowry Acids & Bases HCl + H2O  H3O+ + Cl- Bronsted-Lowry Acids & Bases

Complete or almost complete ionization. Strong Acids & Bases

Ionization occurs only to a slight extent. Weak Acids & Bases

Reactions of Acids with Metals Metal + Acid  H2(g) + salt Reactions of Acids with Metals

Zn(s) + 2HCl  H2(g) + ZnCl2 Zn(s) + HCl  ?

2Al(s) + 6HCl  3H2(g) + 2AlCl3 Al(s) + HCl  ?

Neutralization Reactions Acid + Base  Salt + H2O Neutralization Reactions

Net Ionic Equation for Neutralization Reactions H+ + OH-  H2O Net Ionic Equation for Neutralization Reactions

Moles H+ = Moles OH- At neutralization

Molarity = Moles solute Liters of soln Molarity (M)

MaVa = MbVb Titration Equation

-log[H+] or –log[H3O+] pH

-log[OH-] pOH

14 pOH + pH =

The pH = The pOH = The [OH-] = 3 11 1 X 10-11 If the [H+] = 1 X 10-3

Substance that changes color over a narrow pH range. Indicator

Molarity H2SO4 Vs. Molarity H+ H2SO4  2H+ + SO42- [H+] = 2[H2SO4] 2M H2SO4  4M H+ Molarity H2SO4 Vs. Molarity H+

MaVa = MbVb X(20.0 mls) = .250M(50.0mls) What is the concentration of a hydrochloric acid solution if 50.0 mL of a 0.250 M KOH solution are needed to neutralize 20.0 mL of the HCl solution of unknown concentration?

(1.50 M)(10.62 mls) = X(20.20 mls) Acid 1.50 M Base ? M Final Volume 16.07 24.25 Initial Volume 5.45 4.05 Amount Used 10.62 20.20 (1.50 M)(10.62 mls) = X(20.20 mls)