Presented by:Group 4, Sec. A – 4L

INTRODUCTION

Introduction | Principles

Introduction | Principles

To know the concentration of an acid or base, the ACID – BASE

TITRATION is used.

Introduction | Principles

TITRATION is the gradual addition of one solution until the solute in the first solution has reacted completely with the solute in

the second solution

Introduction | Principles

Introduction | Principles

OBJECTIVES

Introduction | Objectives

Materials | Reagents

REAGENTS

0.5 gram Sodium Hydroxide (NaOH) Pellets

0.150 gram Potassium Acid Phthalate (HKC8H4O4)

Four 75 mL Soft drinks Sample (Colorless or Slightly Colored)

Phenolphthalein

Materials | Apparatus

APPARATUS

50 mL Buret

250 mL Beaker

10 mL Pipet

100 mL Volumetric Flask

Triple Beam Balance

Two 250 mL Erlenmeyer Flask

Materials | Apparatus

APPARATUS

Iron Stand and Ring

Bunsen Burner

Stirring Rod

Buret Clamp

Wire Gauze

I. Preparation of a 0.125 M Sodium Hydroxide (NaOH) Solution

Procedure | Preparation of a 0.125 NaOH Solution

Procedure | Preparation of a 0.125 NaOH Solution

Procedure | Preparation of a 0.125 NaOH Solution

Procedure | Preparation of a 0.125 NaOH Solution

II. Standardization of the NaOHSolution

Procedure | Standardization of the NaOH Solution

Procedure | Standardization of the NaOH Solution

III. Determination of the Acidity of Soft drinks

Procedure | Determination of the Acidity of Softdrinks

Procedure | Determination of the Acidity of Softdrinks

Data and Observations

Table 1. Preparation of the NaOH Solution

MASS (IN GRAMS)

Pellets + Beaker (before standing)

111.90 g

Pellets + Beaker (after standing)

111.94 g

Beaker 111.40 g

Pellets (Before Standing) 0.50 g

Pellets (After Standing) 0.54 g

Data and Observations

Table 2. Standardization of the NaOH Solution

TRIAL 1 TRIAL 2

Mass of Potassium Acid Phthalate (grams)

0.15 g 0.15 g

Final Reading of Buret(mL)

7.40 mL 14.80 mL

Initial Reading of Buret(mL)

0.00 mL 7.40 mL

Volume of NaOH solution used (mL)

7.40 mL 7.40 mL

Molarity of the NaOHSolution (mol/L)

0.099 mol/L 0.099 mol/L

Average Molarity of the NaOH Solution (mol/L)

0.099 mol/L(9.9 x 10-2 mol/L)

Data and Observations

Table 3. Titration of the Soft drink sample with NaOH solution

SOFTDRINK SAMPLE 1Sprite

SOFTDRINK SAMPLE 2Mountain Dew

TRIAL 1 TRIAL 2 TRIAL 1 TRIAL 2

Volume of Softdrinksample used (mL)

20.00 mL 20.00 mL 20.00 mL 20.00 mL

Final Buret Reading(mL)

21.90 mL 32.3 mL 36.7 mL 41.3 mL

Initial Buret Reading(mL)

18.20 mL 28.50 mL 32.3 mL 36.9 mL

Volume of NaOH used (mL)

3.70 mL 3.80 mL 4.2 mL 4.4 mL

Moles NaOH used (moles)

0.00037moles

0.00038 moles

0.00042 moles

0.00044 moles

Data and Observations

Table 4. Acidity of Softdrinks

SOFTDRINK SAMPLE 1Sprite

SOFTDRINK SAMPLE 2Mountain Dew

TRIAL 1 TRIAL 2 TRIAL 1 TRIAL 2

Moles Acid present in a 20 mL Softdrink sample

0.00037 moles

0.00038 moles

0.00042 moles

0.00044 moles

Concentration (in molarity ) of Acid

0.0185 M 0.019 M 0.021 M 0.022 M

Average Molarity of Acid 0.01875 M 0.0215 M

Mass of Citric Acid present in an 8 ounce bottle

0.088 g 1.0 g

Table 1. Preparation of the NaOH Solution

Sample Calculations

MASS (IN GRAMS)

Pellets (Before Standing) 0.50 g

Pellets (After Standing) 0.54 g

Sample Calculations

Table 2. Standardization of the NaOH Solution

Sample Calculations

Sample Calculations

Sample Calculations

Sample Calculations

Sample Calculations

Table 2. Standardization of the NaOH Solution

Sample Calculations

Sample Calculations

Sample Calculations

Sample Calculations

Sample Calculations

Table 3. Titration of the Soft drink sample with NaOH solution

Sample Calculations

Sample Calculations

Sample Calculations

Sample Calculations

Sample Calculations

Sample Calculations

General Chemistry and Chemical Education Division,Institute of Chemistry, College of Arts and Sciences,UPLB. 2005. Laboratory Manual for Chemistry 16. 3rd

Ed. Los Baños: University of the Philippines – LosBaños. pp. 71 - 74

REFERENCES

References