1. Reactions in Aqueous Solutions
AP Chemistry

2. Water and Electrolytes

3. 4.1 Water, the Common Solvent
Many substances ____________________ in water
Shape is ____________; bond angle of 104.5o
Because oxygen is more electronegative than hydrogen, the water molecule is _______________
dissolve
bent
polar

4. bent
polar

5. Hydration-interaction between solute particles and water molecules
Example: NaCl dissolved in water

6. Solubility- the amount of a substance that dissolves in a given volume of solvent at a given temperature

7. “Like dissolves like” polar dissolves polar
nonpolar dissolves nonpolar
polar does not dissolve nonpolar
nonpolar does not dissolve polar

8. Alcohols are soluble in water because both are polar

9. 4.2 The Nature of Aqueous Solutions: Strong and Weak Electrolytes
Solution: homogeneous mixture
Solute: substance dissolved in a liquid to form a solution
Solvent: dissolving medium (often water)

10. Electrical conductivity: ability to conduct electricity; electrolytes do and nonelectrolytes do not

11. Arrhenius: extent to which a solution can conduct electricity depends directly on the number of ions present
1899

12. Arrhenius acid: produces H+ in solution
Arrhenius base: produces OH- in solution

13. Strong electrolytes: strong acids, strong bases, soluble salts (ionic compounds)
Ionic compounds conduct electricity when molten or dissolved in water

14. Strong Acids: ionize (dissociate) completely; 100%
Strong bases: completely ionize in solution, 100%

15. Seven strong acids to memorize:
HCl
HBr HI
HNO3
HClO3
HClO4
H2SO4

16. Eight Strong Bases Group 1: LiOH NaOH KOH RbOH CsOH “Heavy” Group 2:
Ca(OH)2
Sr(OH)2
Ba(OH)2

17. Two Strong Bases to Memorize
NaOH
KOH
These are the most common and are the only ones we will use in the lab

18. Weak electrolytes: exhibit small degree of ionization, 1%

19. Weak acids:
all acids except the seven strong acids are weak
acetic acid (HC2H3O2)
Weak bases:
all bases except the eight strong bases are weak
ammonia (NH3)

20. molecules do not dissociate even though they are soluble
Nonelectrolytes:
molecules do not dissociate even though they are soluble
covalent compounds
Examples:
ethanol (C2H3OH)
sucrose (C12H22O11)

21. Dissociation Equations
Occur in water (aqueous solution)
Be sure and include state symbols
Google the compound to find out its most common STP if you are not sure

22. Examples of Dissociation Equations:
HCl (aq) →
HNO3 (aq) →
NaOH (s) →
NH3 (aq) + H2O (l) →
H+ (aq) + Cl- (aq)
H+ (aq) + NO3 (aq)
Na+ (aq) + OH- (aq)
NH4+ (aq) + OH- (aq)