1. Chapter 4: Reactions in Aqueous Solutions

2. A solution is a homogenous mixture of 2 or more substances
The solute is(are) the substance(s) present in the smaller amount(s)
The solvent is the substance present in the larger amount
In aqueous solutions (aq)
*solvent is water
*solute can be ionic compounds, aqueous acids,
bases, or molecular compounds
4.1

3. An electrolyte is a substance that, when dissolved in water, results in a solution that can conduct electricity. So Gatorade is just glorified salt water…
A nonelectrolyte is a substance that, when dissolved, results in a solution that does not conduct electricity.
nonelectrolyte
weak electrolyte
strong electrolyte
4.1

4. 4 Types of Inorganic Compounds
Molecular; Made of 2 or more Nonmetals
Ionic; Made of + and – ion. Generally + ion is from metal and – ion from nonmetal.
Bases; + ion; - ion is hydroxide (OH)-
Aqueous Acid; H+ and – ion dissolved in water. Generally – ion is nonmetal

5. Inorganic Compounds Dissolved in Water ALL BUT MOLECULAR PRODUCE IONS
Ionic Compounds
Na Cl (aq)
2. Bases
Na (OH) (aq)
Na+
Cl-
(OH)-
Na+
3. Aqueous Acids
HCl (aq)
4. Molecular
ICl (aq)
NO Ions!
Cl- H+ I Cl

6. Strong Electrolyte Weak Electrolyte Nonelectrolyte Strong Acids
Weak Acids
Molecular Compounds
Strong Bases
Weak Bases
Ionic Compounds
4.1

7. Electrolytic Solutions Contain Mobile Cations (+) and Anions(-)
Ionic Compounds, Aqueous Acids, and Base Dissociate Into the Ions They are Made of When Dissolved in Water.
NaCl (s)  Na+ (aq) + Cl-(aq)
More Ions in Solutions; Stronger Electrolyte
H2O

8. Weak vs. Strong Electrolyte
A strong electrolyte will produce more ions
when same amount of solid is dissolved in solvent. H+
Cl-
Strong Electrolyte – 100% dissociation
HCl (g) H+ (aq) + Cl- (aq)
H2O
Weak Electrolyte – not completely dissociated
HNO NO2- (aq) + H+ (aq)
H2O
NO2- H+
NO2- H+

9. Precipitation Reactions
Mix two aqueous solutions made by dissolving ionic compounds in water.
If a reaction happens, a precipitate (solid) is formed.

11. Predicting Products of Precipitation Reactions
Ionic Compounds are Strong Electrolytes –Determine charge on all ions of reactants
Using Ion Charges; Predict formula of products. ( + ion of one reactant forms compound with – ion of other reactant)
Balance Equation
Determine is product is solid or aqueous solution

12. Solubility Rules for Common Ionic Compounds In water at 250C
Soluble Compounds
Exceptions
Compounds containing alkali metal ions and NH4+
NO3-, HCO3-, ClO3-
Cl-, Br-, I-
Halides of Ag+, Hg22+, Pb2+
SO42-
Sulfates of Ag+, Ca2+, Sr2+, Ba2+, Hg2+, Pb2+
Insoluble Compounds
CO32-, PO43-, CrO42-, S2-
OH-
Compounds containing alkali metal ions and Ba2+
4.2

13. Predicting Products of Precipitation Reactions (Cont)
Determine spectator ions (Ions that are still dissolved in water in the product)
Write net ionic equation (Only shows ions involved in forming solid)
Same as double replacement reactions from last year  just adding ONE extra step to it.

14. Precipitation Reactions
Precipitate – insoluble solid that separates from solution
PbI2
precipitate
Pb(NO3)2 (aq) + 2NaI (aq) PbI2 (s) + 2NaNO3 (aq)
molecular equation
Pb2+ + 2NO3- + 2Na+ + 2I PbI2 (s) + 2Na+ + 2NO3-
ionic equation
Pb2+ + 2I PbI2 (s)
net ionic equation
Na+ and NO3- are spectator ions
4.2

15. AgNO3 (aq) + NaCl (aq) AgCl (s) + NaNO3 (aq)
Write the net ionic equation for the reaction of silver
nitrate with sodium chloride.
AgNO3 (aq) + NaCl (aq) AgCl (s) + NaNO3 (aq)
Ag+ + NO3- + Na+ + Cl AgCl (s) + Na+ + NO3-
Ag+ + Cl AgCl (s)
4.2

16. Acids
Have a sour taste. Vinegar owes its taste to 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
Bases
Have a bitter taste.
Feel slippery. Many soaps contain bases.
4.3

17. Bronsted Acids Produce H+ (proton) or (H3O)+ when dissolved in water
Proton donor
HNO3 (aq)  H+ (aq) + (NO3)- (aq)
H2O
HNO3 (aq) + H2O (l)  H3O+ (aq) + (NO3)- (aq)

18. Monoprotic acids; Produce one H+ when dissolved in water
HNO H+ + NO3-
Strong electrolyte, strong acid
Diprotic acids; Produce two H+ when dissolved
in water
H2SO H+ + SO4-2
Strong electrolyte, strong acid
Triprotic acids; Produce three H+ when dissolved
in water
H3PO H+ + PO4-3
Weak electrolyte, weak acid
4.3

19. Bronsted Bases Produce (OH)- when dissolved in water
Proton (H+) acceptor
Na(OH) (s) > Na+ (aq) + (OH)- (aq)
H2O
F- (aq) + H2O (l) <-> HF (aq) + (OH)- (aq)

20. Neutralization Reaction
Acid + Base -> Salt + H2O

21. Practice Problem
What is the neutralization reaction of hydrochloric acid and sodium hydroxide?
HCl + NaOH 
Must be a salt and water!
Products: H2O + NaCl
Simple double replacement reaction!
HCl + NaOH  H2O + NaCl