Honors Chemistry
Name: _____________________________________ Date: __________________ Mods: _________

_______________________- the experimental technique used to determine the concentration of a solution with _________________ molarity
► Can be performed with acid/base, precipitation, or redox (oxidation-reduction) reactions

Terms to know:
► __________________ - solution of unknown concentration which is being titrated or
“analyzed”
► __________________ (aka standard solution) – solution of known concentration (or known mass)

Titration Example:
► Analyte = ??? M __________ (unknown concentration) o Begin with a known __________________ of this analyte (say 20.0 mL HCl) in an
Erlenmeyer flask
► Titrant = 0.10 M NaOH o Must be of known ________________________ and placed in a ________________ device which measures/dispenses liquid) o We will monitor how much (what volume) of the titrant is required to
_________________________ ALL the 20.0 mL of HCl analyte
► With calculations, ultimately the molarity of the acid can be determined

Equivalence Point
► How do you known when all the analyte (20 mL HCl) has been neutralized? o Officially, neutralization occurs when there are _____________ quantities of acid & base present in the solution (moles ________ = moles ________) o This point is known as the ____________________________ _____________ (EQ point) of the titration (Note: just because the overall reaction is neutralized, that does
NOT mean it will always have a pH = 7)
► We can’t “count” the moles… so we need some signal to know when the EQ point is achieved o For this, we can use ________________________ (or pH meters, which we will look at later in this chapter)


Indicators – chemical compounds which change color based on the ________ of a solution
► Ex) __________________/___________ indicator: colorless in the presence of ___________ and pink in the presence of _____________

Indicators & Titrations
► Indicator is added to the _______________ solution during a titration o In our example, to the analyte HCl, we can add phenolphthalein indicator (solution will appear ____________________)
► As the titrant (NaOH) is added from the buret to the flask, the neutralization reaction is occurring o Eventually, the EQ point is achieved (H+ & OH- moles are equal… ______________!)
► As soon as _________ extra drop of NaOH is added to the flask past the EQ point, the solution’s pH is now considered basic and the indicator ___________________________ changes color to ___________, signaling the _________ _______________ (stopping point) of the titration.


Titration calculations (aka solution stoichiometry)
► Uses stoichiometry to calculate the unknown molarity of the analyte in a titration o Note: the whole idea of a titration revolves around moles H + = moles OH -
Example #1:
If 20.00 mL of hydrochloric acid is titrated with 16.40 mL of 0.10 M NaOH in order to completely neutralize the acid, find the concentration, in molarity, of the hydrochloric acid.
* Must write out a BALANCED neutralization reaction to start!!!
Example #2:
Tartaric acid, H
2
C
4
H
4
O
6
is neutralized with sodium hydroxide. A sample of 3.0 g of tartaric acid reacts with 45 mL of base. How concentrated is the sodium hydroxide?
Example #3:
Butanoic acid, HC
4
H
7
O
3
, is neutralized with strontium hydroxide. A sample of 4.75 g of butanoic acid reacts with 62.70 mL of base. How concentrated is the strontium hydroxide solution?

Directions: For each problem below, write a neutralization reaction and find the requested quantity:
1) If it takes 54 mL of 0.1 M sodium hydroxide to neutralize 125 mL of a hydrochloric acid solution, what is the concentration of the hydrochloric acid?
2) If it takes 25 mL of 2.8 M hydrobromic acid to neutralize 345 mL of strontium hydroxide solution, what is the concentration of the strontium hydroxide solution?
3) Lactic acid, HC
3
H
5
O
3
, is neutralized with lithium hydroxide. A sample of 0.578 g of lactic acid reacts with 31.11 mL of base. How concentrated is the sodium hydroxide?
4) If it takes 50 mL of 0.5 M potassium hydroxide solution to completely neutralize 125 mL of phosphoric acid solution, what is the concentration of the phosphoric acid solution?

5) A volume of 25.0 mL of nitric acid is titrated with 0.12 M sodium hydroxide. To completely neutralize the acid, 10 mL of sodium hydroxide must be added. Find the concentration of the nitric acid.
6) If 12.0 mL of 1.34 M sodium hydroxide is required to neutralize 25 mL of a sulfuric acid solution, what is the molarity of the sulfuric acid?
7) Acetic acid is neutralized with lithium hydroxide. A sample of 1.04 g of acetic acid reacts with
75.21 mL of base. Determine the concentration of the lithium hydroxide.
8) If 14.7 mL of 0.102 M barium hydroxide is required to neutralize 25.00 mL of a phosphoric acid solution, what is the molarity of the phosphoric acid?

9) A sample of 0.965 g of malonic acid, H
2
C
3
H
2
O
4
, requires 45.91 mL of lithium hydroxide to be neutralized. Determine the concentration of the lithium hydroxide.
10) If 46.2 mL of 2.50 M sodium hydroxide is required to neutralize 25.00 mL of a phosphoric acid solution, what is the molarity of the phosphoric acid?
11) What is the molarity of a sodium hydroxide solution if 15.0 mL is exactly neutralized by 7.5 mL of a 0.02 M acetic acid solution?
12) If 19.1 mL of 0.118 M hydroiodic acid is required to neutralize 25.0 mL of a potassium hydroxide solution, what is the molarity of the potassium hydroxide?

13) Boric acid, H
3
BO
3
, is neutralized with sodium hydroxide. A 1.42 g sample of boric acid reacts with 157 mL of sodium hydroxide. Determine the concentration of the sodium hydroxide.
14) Sulfuric acid is titrated with 0.75 M potassium hydroxide. It requires 328.4 mL of potassium hydroxide to neutralize a 40.00 mL sample of sulfuric acid. Calculate the concentration of the sulfuric acid.
15) Can I titrate a solution of unknown concentration with another solution of unknown concentration and still get a meaningful answer? Explain.