Determination of sulphate by pH titration
1Department of Inorganic and Analytical Chemistry, L. Eötvös University, 1088 Budapest, Múzeum krt. 4/B, Hungary.
Talanta
|April 1, 1987
Summary
A novel, cost-effective analytical method determines sulphate and weak acids/bases using partial protonation or dissociation. This pH titration technique offers broad applicability across various matrices and solvents.
Area of Science:
- Analytical Chemistry
- Electrochemistry
Background:
- Sulphate determination is crucial in environmental and industrial monitoring.
- Existing methods for weak acid/base analysis can be complex or costly.
- Exploiting partial protonation/dissociation for analysis is an underexplored area.
Purpose of the Study:
- To develop a simple, inexpensive, and versatile method for sulphate determination.
- To utilize the analytical potential of partial protonation/dissociation of weak species.
- To establish a robust titration procedure applicable to diverse sample matrices.
Main Methods:
- The method involves three sequential pH titrations: a test solution, the sulphate sample, and a blank.
- It leverages the principle of partial protonation of weak bases or partial dissociation of weak acids.
- The procedure is adaptable for use with various inorganic ions, organic matrices, and solvents.
Main Results:
- Sulphate concentrations above 10(-3)M are determinable in aqueous media.
- The method demonstrates applicability in complex matrices and non-aqueous solvents.
- Employing solvent mixtures can enhance the method's sensitivity by up to two orders of magnitude.
Conclusions:
- A simple, inexpensive, and versatile titration method for sulphate and weak acids/bases has been successfully developed.
- The technique's ability to handle complex matrices and solvents broadens its analytical utility.
- Further optimization using solvent mixtures promises significantly increased sensitivity for trace analysis.
More Related Videos
Related Concept Videos
01:23Titration of Polyprotic Acids with a Strong Base
Titration of a polyprotic acid, which contains multiple ionizable protons, involves distinct dissociation steps, each with its own dissociation constant (Ka). Each successive Ka is weaker than the previous one. In the titration of a polyprotic acid like sulfurous acid with a strong base such as sodium hydroxide, the base first neutralizes the initial ionizable proton, forming an intermediate species (e.g., hydrogen sulfite ions). This step's titration curve resembles that of a weak monoprotic...
02:08Titration of a Polyprotic Acid
A polyprotic acid contains more than one ionizable hydrogen and undergoes a stepwise ionization process. If the acid dissociation constants of the ionizable protons differ sufficiently from each other, then the titration curve for such polyprotic acid generates a distinct equivalence point for each of its ionizable hydrogens. Therefore, titration of a diprotic acid results in the formation of two equivalence points, whereas the titration of a triprotic acid results in the formation of three...
01:19Precipitation Titration: Endpoint Detection Methods
In argentometric precipitation titrations, endpoints can be detected visually by the Mohr, Volhard, and Fajans methods. In the Mohr method, adding a soluble chromate indicator gives an initial yellow color to the analyte solution. As the titrant is added, the first excess of silver ions forms a red silver chromate precipitate, marking the endpoint. The solution pH should be maintained at about 8 by adding solid CaCO3.
In the Volhard method, a standard excess of AgNO3 is first added to the...
In the Volhard method, a standard excess of AgNO3 is first added to the...
01:18Titration of Polyprotic Base with a Strong Acid
The titration of a polyprotic base such as sodium carbonate with a strong acid such as hydrochloric acid results in two equivalence points on the titration curve. At the first equivalence point, the carbonate ions in the base are completely converted to bicarbonate ions. The second equivalence point corresponds to the complete conversion of bicarbonate ions to carbonic acid, which dissociates into carbon dioxide and water. The region before the first equivalence point corresponds to the...
01:26Acid–Base Titration: Overview
An acid-base titration is a technique used to determine the concentration of an unknown acid or base, using a titrant of known concentration–either a base for acid titration or an acid for base titration. The process involves gradually adding the titrant, leading to a predictable change in the pH of the solution. This change is plotted on a titration curve, showing how a solution's pH varies with the amount of titrant added. Such curves are instrumental in monitoring the titration's progress...
02:28Titration Calculations: Strong Acid - Strong Base
Calculating pH for Titration Solutions: Strong Acid/Strong Base
A titration is carried out for 25.00 mL of 0.100 M HCl (strong acid) with 0.100 M of a strong base NaOH. The pH at different volumes of added base solution can be calculated as follows:
(a) Titrant volume = 0 mL. The solution pH is due to the acid ionization of HCl. Because this is a strong acid, the ionization is complete and the hydronium ion molarity is 0.100 M. The pH of the solution is then:
A titration is carried out for 25.00 mL of 0.100 M HCl (strong acid) with 0.100 M of a strong base NaOH. The pH at different volumes of added base solution can be calculated as follows:
(a) Titrant volume = 0 mL. The solution pH is due to the acid ionization of HCl. Because this is a strong acid, the ionization is complete and the hydronium ion molarity is 0.100 M. The pH of the solution is then: