quantitative determination of the acidity of soft drinks
TRANSCRIPT
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