Benzoin Lab Report

Preparation of Standard Acid and Base

1/20/15

CHM 3120L Sect:0012

Jacob Sitero

Introduction:

The purpose of this experiment is to prepare standard hydrochloric acid (HCl) and sodium hydroxide (NaOH) solutions. With the use of titration and potassium hydrogen phthalate (KHP), the exact concentration of NaOH can be found. Using the now standardized NaOH solution, a second titration is performed with HCl to find the exact concentration of the acid. With these newfound acid and base standards, they can be used in future experiments for more accurate calculations.

Experiment:

The procedure for this experiment was taken directly from the “CHM 3120L Analytical Chemistry Laboratory Manual. Experiment 1.”

Theory:

Standardization of NaOH:

Calculation: Amount of NaOH to use for titration.

Calculation: Amount of HCl to use for titration.

m1v1=m2v2 v1=

Important definitions for Experiment 1:

Titration- a technique in which a solution of known concentration is used to find the concentration of an unknown solution. This is performed by having known solution in a buret added to the unknown solution until the reaction is complete.

Primary Standard- Extrmely pure reagent which is usually used in titrations to find unknown concentrations or to calibrate instruments.

Results:

Four Samples of KHP:

Sample | Weight (g) | Moles of KHP |

A | 0.7906 | 0.0039 |

B | 0.8244 | 0.0040 |

C | 0.8732 | 0.0043 |

D | 0.0041 | 0.0041 |

Titration of NaOH:

1:1 Ratio moles NaOH=moles KHP

Trial A:

Trial B:

Trial C:

Trial D:

Average Molarity= 0.086 NaOH

Titration of HCl:

1:1 Ratio moles NaOH=moles HCl

Trial A: HCl

T