Lab Report on Acid-Base Titration
1. Aim: To determine the weight-to-volume percent of acetic acid present in commercial vinegar and the weight-to-volume percent of ammonia present in window cleaners. Acid-base titrations can be conducted using the above samples against standardized aqueous NaOH and standardized aqueous HCl solutions respectively.
2. Introduction:
Acetic acid, commonly known as ethanoic acid CH3COOH, is found in commercial vinegar. It is a weak organic acid that gives vinegar its characteristic pungent smell, sour taste and slight acidity. Being an acid, vinegar is used as a mild disinfectant in cleaning agents as well as a food preservative. Ammonia, NH3, is used in household and industrial cleaning agents due to its ability to solubilize grease. In this experiment, we shall use acid-base titration to determine the weight-to-volume percentage of acetic acid and ammonia. An acid-base titration is a process of obtaining quantitative information of a sample using an acid-base reaction by reacting with a certain volume of reactant whose concentration is known. A suitable indicator for determining the equivalence point is used to indicate the end point of an acid-base titration. To achieve accurate results, multiple titrations will be carried out until duplicate determinations agree to within 0.05mL of each other.
4. Results & Calculations:
4.1 Standardization of NaOH
Molarity of KHC8H4O4 is 0.05044 moldm-3 ( = = 0.05044 moldm-3)
Titration
1
2
3
Final volume of titrant/cm3
5.00
10.00
14.80
Initial volume of titrant/cm3
0.00
5.00
10.00
Volume of titrant used/cm3
5.00
5.00
4.80
KHC8H4O4 (aq) + NaOH (aq) KHC8H4O3 - Na+ (aq) + H2O (l)
Average volume of NaOH titrate used = ½ (5.00 + 5.00) = 5.00 cm3
No. of moles of KHC8H4O4 reacted = 0.01 × 0.05044 = 5.044 x 10-4 mol
From the equation, mole ratio of NaOH ≡ KHC8H4O4 is 1:1, No. of moles of NaOH reacted = 5.044 x 10-4 mol
2. Introduction:
Acetic acid, commonly known as ethanoic acid CH3COOH, is found in commercial vinegar. It is a weak organic acid that gives vinegar its characteristic pungent smell, sour taste and slight acidity. Being an acid, vinegar is used as a mild disinfectant in cleaning agents as well as a food preservative. Ammonia, NH3, is used in household and industrial cleaning agents due to its ability to solubilize grease. In this experiment, we shall use acid-base titration to determine the weight-to-volume percentage of acetic acid and ammonia. An acid-base titration is a process of obtaining quantitative information of a sample using an acid-base reaction by reacting with a certain volume of reactant whose concentration is known. A suitable indicator for determining the equivalence point is used to indicate the end point of an acid-base titration. To achieve accurate results, multiple titrations will be carried out until duplicate determinations agree to within 0.05mL of each other.
4. Results & Calculations:
4.1 Standardization of NaOH
Molarity of KHC8H4O4 is 0.05044 moldm-3 ( = = 0.05044 moldm-3)
Titration
1
2
3
Final volume of titrant/cm3
5.00
10.00
14.80
Initial volume of titrant/cm3
0.00
5.00
10.00
Volume of titrant used/cm3
5.00
5.00
4.80
KHC8H4O4 (aq) + NaOH (aq) KHC8H4O3 - Na+ (aq) + H2O (l)
Average volume of NaOH titrate used = ½ (5.00 + 5.00) = 5.00 cm3
No. of moles of KHC8H4O4 reacted = 0.01 × 0.05044 = 5.044 x 10-4 mol
From the equation, mole ratio of NaOH ≡ KHC8H4O4 is 1:1, No. of moles of NaOH reacted = 5.044 x 10-4 mol