What is the analyte in iodometric titration?
What is the analyte in iodometric titration?
o Indirect Titration: The analyte forms a compound with the species that reacts with the titrant. o Back Titration: A known excess of titrant is added to the analyte. The excess of titrant is titrated with a standard solution. o Iodometry: This type is new for you.
Why excess potassium iodide is used in iodometric titration?
Excess KI is added to help solubilise the free iodine, which is quite insoluble in pure water under normal conditions. The preferred water for this method should be boiled distilled water, which requires provision of a distillation unit.
Why iodometric titrations are done quickly?
In these cases the titration of the liberated iodine must be completed quickly in order to eliminate undue exposure to the atmosphere since an acid medium constitutes an optimum condition for atmospheric oxidation of the excess iodide ion.
Why is iodine solution unstable?
Thiosulfate is unstable in the presence of acids, and iodides in low pH can be oxidized by air oxygen to iodine. Iodine is very weakly soluble in the water, and can be easily lost from the solution due to its volatility. However, in the presence of excess iodides iodine creates I3- ions.
Why we add H2SO4 in iodometric titration?
Sulphuric Acid (H2SO4) is used in the redox titration process because it provides the H(+) ions necessary for the reaction to occur more quickly whilst the sulphate(-) ions barely react during the reaction. Therefore, sulfuric acid is added to make the solution acidic.
What are the advantages of titration?
Titrimetric analysis commonly referred to as volumetric analysis offers distinct advantages over cumbersome gravimetric methods:
- Speed of analysis.
- Instantaneous completion of reactions.
- Greater accuracy due to minimization of material loss involved in decanting, filtration, precipitation or similar operations.
Why is iodine Coloured?
The iodine is a bluish-black solid (at room temperature) with a metallic luster sublimating into violet-pink gas. And we know that this colour of iodine is because of the absorption of visible light by an electronic transition between highest and lowest molecular orbitals.
Why hno3 is not used in titration?
The acid used in this titration is dilute sulphuric acid. Nitric acid is not used as it is itself an oxidising agent and hydrochloric acid is usually avoided because it reacts with KMnO4 according to the equation given below to produce chlorine and chlorine which is also an oxidising agent in the aqueous solution.
Why nahco3 is added in iodometric titration?
Thiosulfate is unstable under acidic pH conditions, causing the thiosulfate to decompose into sulfur dioxide, elemental sulfur, and water. Sodium carbonate in solution is alkaline, and the abundance of hydroxide anions prevents the thiosulfate from encountering the positive charges that would trigger its decomposition.
What is iodometry and iodimetry titration?
Iodometry is a titration where the iodine produced in the previous redox reaction is titrated with a reducing agent whereas iodimetry is a titration where iodine solution is directly titrated with the reducing agent; Iodometry is an indirect method of analysis whereas iodimetry is a direct method of analysis; Iodometry entails two redox reaction whereas iodimetry entails a single redox reaction
What is a titrant in a titration?
In analytical chemistry, the titrant is a solution of known concentration that is added (titrated) to another solution to determine the concentration of a second chemical species. The titrant may also be called the titrator, the reagent, or the standard solution.
What is iodine titration?
Iodometry, known as iodometric titration, is a method of volumetric chemical analysis, a redox titration where the appearance or disappearance of elementary iodine indicates the end point.
