1. Lab 20- Acids & Bases
Titration

2. A. Neutralization Chemical reaction between an acid and a base.
Products are a salt (ionic compound) and water.

3. ACID + BASE  SALT + WATER
Neutralization
ACID + BASE  SALT + WATER
HCl + NaOH  NaCl + H2O
strong
strong
neutral
HC2H3O2 + NaOH  NaC2H3O2 + H2O
weak
strong
basic
Salts can be neutral, acidic, or basic.
Neutralization does not mean pH = 7.

4. Titration
standard solution
unknown solution
Titration
Analytical method in which a standard solution is used to determine the concentration of an unknown solution.

5. B. Titration Equivalence point (endpoint)
Point at which equal amounts of H3O+ and OH- have been added.
Determined by…
indicator color change
dramatic change in pH

6. moles H3O+ = moles OH- MV n = MV n B. Titration M: Molarity
V: volume
n: # of H+ ions in the acid or OH- ions in the base

7. B. Titration
42.5 mL of 1.3M NaOH are required to neutralize 50.0 mL of KHP. Find the molarity of KHP.
H3O+
M = ?
V = 50.0 mL
n = 1
OH-
M = 1.3M
V = 42.5 mL
n = 1
MV = MV
M(50.0mL)
=(1.3M)(42.5mL)
M = 1.11 M H2SO4

8. Procedures Data you need for part A KHP =204.2g/mol Formulas
M = mol/liters
moles H3O+ = moles OH-
MV (H3O+) = MV (OH-)
% KHP = mass of KHP/ Mass of mixture

9. Procedures A. Standardization of NaOH
Add 2.5 grams of KHP into 3 Erlenmeyer flasks
Use analytical balance to 4 sig figs
Add 100 ml of D.I water into each flask
Add 2 drops of Phenolphthalein soln

10. Slowly add NaOH into 1st flask, while swirling flask
A. Fill a Burett with NaOH (aq)
Slowly add NaOH into 1st flask, while swirling flask
See fig 20-2 and read procedures for proper titration
Record amount of NaOH used to titrate

11. calculations Determine moles of KHp Determine moles of NaOH
Determine Molarity of NaOH
Determine Standard deviation
(do this at home, see pgs )

12. Part B . Standardization of unKnown acid
Add 2.5 grams of unknown acid into 3 Erlenmeyer flasks
Use analytical balance to 4 sig figs
Add 100 ml of D.I water into each flask
Add 2 drops of Phenolphthalein soln

13. Slowly add NaOH into 1st flask, while swirling flask
A. Fill a Burett with standarized NaOH
Slowly add NaOH into 1st flask, while swirling flask
See fig 20-2 and read procedures for proper titration
Record amount of NaOH used to titrate

14. calculations Determine moles of base used Determine moles of KHP
Determine mass of KHp
Determine % of KHP in unknown