1. SELF-IONIZATION OF WATER
A. To understand whether a solution is an acid or a base, we’ll use pure water as a __________ starting point.
NEUTRAL

2. SELF-IONIZATION OF WATER
B. Although pure water is mostly molecules of H2O, conductivity measurements indicate a small amount of ______ are present from the _________________ of small amounts of the water molecules.
ions
SELF-IONIZATION

3. SELF-IONIZATION OF WATER
1. In the self-ionization of water, two water molecules produce a hydronium ion. H3O+, and a hydroxide ion, OH-.

4. SELF-IONIZATION OF WATER
2. The self-ionization of water produces _______ amounts of hydrogen and hydroxide ions at a concentration of __________ each (at 25°C). Because these ions are in equal concentrations, we say that pure water is __________.
EQUAL
1.0X10-7M
NEUTRAL

5. SELF-IONIZATION OF WATER
C. The equilibrium constant, Kw, for the self-ionization of water at 25oC is, therefore, equal________.
1x10-14

6. SELF-IONIZATION OF WATER
Kw = [H1+] [OH1-]
Kw = (1.0x10-7M) (1.0x10-7M)
Kw = __________
1.0X10-14

7. SELF-IONIZATION OF WATER
1. Notice that the equilibrium constant expression, Kw, does NOT include [REACTANTS], because the reactant is ______.
liquid

8. SELF-IONIZATION OF WATER
2. REMEMBER that a K value that is less than 1 indicates there is a LOT of _________ present at equilibrium. In other words, water is mostly water molecules and there is very little H3O+ or OH-.
Reactants

9. SELF-IONIZATION OF WATER
3. Recognize that the reaction for the self-ionization of water is _____________ (energy is put in to break the bonds of the water molecules), and like other reactions, the Kw value will be affected by temperature
endothermic