Titration Notes, part I Neutralization Reactions.

Titration Notes, Titration Notes, part Ipart INeutralization ReactionsNeutralization Reactions

NeutralizationA reaction in which an acid and a

base in aqueous solution produces a salt and water.

What is a salt?An ionic compound made from the

cation of a base and the anion of an acid.

Neutralization ReactionsNaOH + HCl NaOH + HCl

KOH + HKOH + H22SOSO44

Lithium hydroxide neutralizes nitric Lithium hydroxide neutralizes nitric acidacid

Phosphoric acid neutralizes calcium Phosphoric acid neutralizes calcium hydroxidehydroxide

Titration ReactionsYou can use a neutralization

reaction to determine the concentration of an acid (or base) solution…

……using stoichiometry!!!using stoichiometry!!!

IndicatorsIn order to do so, you need an

indicator—a dye that changes colors at different pH

In most titrations, phenolphthalein is used, because it turns from colorless to bright pink as a solution goes from acidic to basic.

How Do You Titrate?1) A measured amount of acid

solution of unknown concentration is added to a flask.

2) Indicator is added to the acid.3) Measured volumes of a base of

known concentration are added until the indicator barely changes color.

Titration TermsA A buretburet is the device that we is the device that we

use for measuring volumes use for measuring volumes in a titration.in a titration.

Titration TermsThe standard solution is the solution

of known concentration added in step #3.

Titration TermsThe endpoint is the point at which

the indicator changes color.

The Mathematics of TitrationDon’t forget, the big M that stands

for molarity is the same thing as moles/Liter!

Practice Problem #1A 25mL solution of H2SO4 is

neutralized by 18mL of 1.1M NaOH. What is the molarity of the H2SO4?

Practice Problem #2A 19.0mL solution of H3PO4 is

neutralized by 22.7mL of 2.3M Ca(OH)2. What is the molarity of the H3PO4?

Practice Problem #3How much 1.3M HCl is needed to

neutralize 39.6mL of 2.1M NaOH?

Practice Problem #4How much 2.9M NaOH would be

needed to neutralize 42.7mL of 3.1M H2SO4?