Testing

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Types of Solutions

• 1. Electrolytes Completely Break up into ions
  in water (Arrhenius, 1884 (Nobel Prize, 1903)).
• a. Many Ionic Compounds and strong acids (HCl,
  HBr, HI, HNO3, H2SO4,HClO4)
• b. Different than decomposition because ions are
  produced.

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Types of Solutions

• c. Examples
• NaCl(s) ? Na(aq) Cl-(aq)
• CaCl2(s) ? Ca2(aq) 2Cl-(aq)
• Al2(SO4)3(s) ? 2Al3(aq) 3SO42-(aq)

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Types of Solutions

• d. Examples
• Na2CO3(s) ?
• (NH4)2Cr2O7(s) ?
• HCl(l) ?
• FeCl3(s) ?
• e. Hydration Sphere for NaCl

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Types of Solutions

• 2. Weak Electrolytes
• a. Weak Acids
• b. Examples (Write eq. eqn.)
• HC2H3O2, HF, HNO2

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Types of Solutions

• 3. Non-Electrolytes- Do not break up into ions
  in water
• a. Many Molecular Compounds
• b. Some are still soluble, they just dont form
  ions
• C12H22O11(s) ? C12H22O11(aq)
• Do Drawing

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Types of Reactions
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Types of Solutions
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Solubility Rules

• Provide a rough idea of whether something will
  dissolve in water
• DO NOT GIVE ACTUAL, NUMERICAL SOLUBILITIES (you
  must look in a book or do an experiment)

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Solubility Rules
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Solubility Rules

• Examples
• Na2CO3(s)?
• Na2S (s) ?
• Cu(C2H3O2)2(s) ?
• NaOH (s) ?
• CuCO3 (s) ?

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Solubility Rules

• Examples
• PbSO4(s) ?
• AgBr(s)?
• KCl(s) ?
• Fe(OH)3(s) ?
• FeSO4(s) ?

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Net Ionic Rxns

• Many are Double Replacement Rxns
• Write the complete eqn (including states) for the
  reaction of
• Pb(NO3)2(aq) KI(aq) ?

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• BaCl2(aq)K2SO4(aq)?

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Net Ionic Rxns

• Practice
• AgNO3(aq) BaCl2(aq) ?

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Writing Net Ionic Rxns

• Spectator Ions Ions present in soln, but do not
  take part in the rxn

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• Write complete and net ionic eqns for
• CaCl2(aq) Na2CO3(aq) ?
• NaNO3(aq) NH4OH(aq) ?
• BaCl2 and K2SO4 ?
• Fe2(SO4)3 LiOH ?

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Net Ionic Rxns

• The driving force for many reactions is the
  formation of a
• a) Solid (precipitate) weve just seen these
• b) Liquid
• c) Gas

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Water forming Rxns

• A special type of double replacement -
  neutralization
• Acids
• a. produce H
• b. Often start with H (HCl)
• Bases
• a. produce OH-
• b. Hydroxides (Drano, NaOH)

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Water forming Rxns

• NaOH (aq) HCl (aq) ?
• HClO4 (aq) LiOH (aq) ?
• Ca(OH)2(aq) HNO3 (aq) ?
• Mg(OH)2(s) HCl (aq) ?
• Demo

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Gas forming Rxns

• Carbonates plus acids
• Carbonic acid unstable (in soda)
• H2CO3(aq) ? H2O(l) CO2(g)
• 3. Examples
• CaCO3(s) HCl(aq) ?
• MgCO3(s) HNO3(aq) ?

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• NaHCO3(aq) HNO3(aq) ?
• Na2S(aq) HCl(aq) ?

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Net Ionic Rxns

• Mixed Types
• Fe(NO3)3(aq) Na2CO3(aq)?
• SrCO3(s) HCl(aq) ?
• HBr (aq) LiOH (aq) ?

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Two Types of Chemical Rxns

• Exchange of Ions no change in charge/oxidation
  numbers
• Acid/Base Rxns
• NaOH HCl

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• Precipitation Rxns
• Pb(NO3)2(aq) KI(aq)
• Dissolving Rxns
• CaCl2(s) ?

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• Exchange of Electrons changes in oxidation
  numbers/charges
• Cu(s) 2AgNO3(aq) ? Cu(NO3)2(aq) 2Ag(s)
• Remove spectator ions
• Cu(s) 2Ag(aq) ? Cu2(aq) 2Ag(s)
• Protons
• Electrons

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Oxidation Numbers

• Involves taking compounds apart
• Oxidation numbers Pretend charges for all
  compounds (as if they exist as a monoatomic ion)
• Rules

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Fe H2 P4 Cl2
Elements 0
Monoatomic Ions Charge
Na O2- Al3
Use bankables to calculate the rest
H2S Cl2O Na2SO4 Fe2O3 PO43-
NO3- CaCr2O7 SnBr4
Gr I Gr II
O-2
H
F-
the higher the oxidation , the more oxidized
the element
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Review of Oxidation Numbers

• Calculate the oxidation numbers for
• HClO Cr3
• S8 Fe2(SO4)3
• Mn2O3 SO32-
• KMnO4 NO3-
• HSO4-

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Oxidation

• Classical Definition addition of oxygen
• Fe O2 ? Fe2O3
• Modern Definition an increase in oxidation
  number
• Na O2 ? Na2O
• 0
  1
• Na was oxidized

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Reduction

• Classical Definition addition of hydrogen
• N2 3H2 ? 2NH3 (Haber process)
• R-CC-R H2 ?
• H H
• (unsaturated fat) (saturated fat)

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Reduction

• Modern Definition decrease (reduction) in
  oxidation number
• N2 3H2 ? 2NH3
• 0 -3
• N was reduced

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• H2 Cl2 ? 2HCl
• 0 -1
• Cl was reduced

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Example

• In the following rxns, which element is oxidized,
  which is reduced?
• Al HBr ? AlBr3 H2
• Fe Cu(NO3)2 ? Fe(NO3)2 Cu
• H2 O2 ? H2O

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Activity Series

• Used to predict if a particular redox reaction
  will occur
• Redox reactions - also called single replacement
  reactions
• Not every element can replace every other
• Higher elements get oxidized
• Lower elements get reduced

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• Will Copper metal replace silver in an aqueous
  solution of silver nitrate?

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• Will aqueous iron(II)chloride oxidize magnesium
  metal?

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• Which of the following metals will be oxidized by
  Pb(NO3)2 Zn, Cu, and/or Fe?

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Molarity

• 1. Molarity measure of the concentration of a
  solution
• 2. Molarity moles/liter
• Similar to Density g/L

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Molarity

• 3. Which is more concentrated?
• 1 M HCl 3 M HCl
• Crowded classroom example

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Molarity

• 1. What is the molarity of a soln that contains
  49.0 g of H2SO4 in enough water to make 250.0 mL
  of soln? (Ans 2.00 M)
• 2. What is the molarity of a soln made by
  dissolving 23.4 g of Na2SO4 in enough water to
  make 125 mL of soln? (Ans 1.32 M)

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Molarity

• 3. What mass of HCl is present in 155 mL of 0.540
  M HCl? (Ans 3.06 g)
• 4. How many grams of NaOH are in 5.00 mL of
  0.0900 M NaOH? (Ans 0.018 g)

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Molarity

• 5. What volume of 0.0900 M NaOH is needed to
  provide 0.00058 moles? (Ans 6.44 mL)
• 6. What volume of 0.0764 M HCl is needed to
  provide 0.0694 g of HCl?(Ans 25 mL)

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Molarity

• What is the concentration of all the ions in the
  following solutions?
• 2 M NaOH
• 2 M Ca(OH)2
• 0.08 M K3PO4

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Mixing From a Solid

• 1. Mixing from a solid
• 2. How would you prepare 350.0 mL of 0.500 M
  Na2SO4? (Ans dilute 24.9 g to 350 mL)

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Mixing From a Solid

• 3. How would you prepare 500.0 mL of 0.133 M
  KMnO4? (Ans dilute 10.5 g to 500 mL)
• 4. How would you prepare 250.0 mL of 0.00200 M
  NaOH? (Ans dilute 0.02 g to 250 mL)

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Diluting from a Solution

• 1. Dilution Formula
• M1V1 M2V2
• 2. Used when you are starting with a more
  concentrated soln. (Grape juice concentrate,
  Coke syrup)

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Diluting from a Solution

• 3. What is the molarity of a soln of KCl that is
  prepared by diluting 855 mL of 0.475 M soln to a
  volume of 1.25 L? (Ans 0.325 M)
• 4. You have a 3.00 L bottle of 11.3 M HCl. What
  volume of it must be diluted to make 1.00 L of
  0.555 M HCl? (Ans 49.1 mL)

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Solution Reactions

• How many grams of water form when 25.0 mL of
  0.100 M HNO3 is completely neutralized by NaOH?
  (Ans 0.045 g)
• What volume of 0.500 M HCl is needed to react
  completely with 33.1 g of Pb(NO3)2? (Ans 400.0
  mL)

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Solution Reactions

• What is the molarity of an NaOH soln if 22.0 mL
  is needed to neutralize 15.0 mL of 0.100 M HCl?
  (Ans 0.0682 M)
• What is the molarity of an NaOH soln if 48.0 mL
  is needed to neutralize 35.0 mL of 0.144M H2SO4?
  (Ans 0.210 M)

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• Will barium metal reduce nickel(II)nitrate?
• Will iron(II)chloride oxidize calcium metal?
• Will aluminum chloride oxidize gold?

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• Fe(NO3)2(s) ? (placed in water)
• C2H6(g) O2(g) ?
• K2CO3(aq) Fe(NO3)2(aq) ?
• K(s) CoCl2(aq) ?
• Mg(OH)2(s) HCl(aq) ?
• CaCl2(aq) Ag(s) ?

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• Write net ionic equations
• NaHCO3(aq) HNO3(aq) ?
• MgCO3(s) HNO3(aq) ?
• BaCl2(aq) H2SO4(aq) ?
• Write eqns if they occur
• Fe(NO3)2(s) ? (placed in water)
• PbSO4(s) ? (placed in water)
• Sn(s) HCl(aq) ?
• Pt(s) NiCl2(aq) ?
• Identify any substances oxidized or reduced