What do you mean by iodometric estimation?

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. The iodometric titration is a general method to determine the concentration of an oxidising agent in solution.

What is the procedure of iodometric titration?

Add to Erlenmeyer flask 50 mL of demineralized water, 10 mL of sulfuric acid solution, 10-15 mLs of potassium iodide solution, and two drops ammonium molybdate solution. Titrate with 0.1 N sodium thiosulfate to faint yellow or straw color. Swirl or stir gently during titration to minimize iodine loss.

What is the complex formed in the iodometric titrations and what is its color?

As has been mentioned above, the endpoint in a titration of iodine with thiosulfate is signaled by the color change of the starch indicator. When starch is heated in water, various decomposition products are formed, among which is beta-amylose which forms a deep blue-black complex with iodine.

Why is ammonium thiocyanate added in the iodometric estimation of copper with thiosulphate?

Lab practice shows that the end point is sharper when we add some thiocyanate to the solution. Copper (I) thiocyanate is slightly less soluble than iodide, which makes concentration of Cu+ even lower, increasing the oxidation potential of the Cu2+/Cu+ system.

What is the difference between iodometric and Iodimetric solution?

Iodimetric titrations: When an analyte (a reducing agent) is titrated directly with a standard iodine solution, the method is known as iodimetry….Complete answer:

What is the hypo solution?

Hypo Solution is the abbreviation for sodium thiosulphate or sodium hyposulphite. It is used for both film and photographic paper processing, the sodium thiosulfate is known as a photographic fixer and is often referred to as ‘hypo’, from the original chemical name, hyposulphite of soda.

Which type of titration method is used for dissolved oxygen estimation?

The Winkler Method
The Winkler Method uses titration to determine dissolved oxygen in the water sample. A sample bottle is filled completely with water (no air is left to skew the results).

What is the difference between iodometric and Iodimetric titration?

What is the basic difference between iodometric and Iodimetric titration?

Iodometry is the quantitative analysis of a solution of an oxidizing agent by adding an iodide that reacts to form iodine whereas iodimetry is a volumetric analysis involving either titration with a standardized solution of iodine.

What is the role of Kscn in the iodometric titration?

The KSCN is added to displace the adsorbed I2 making it accessible to the starch collodial particles, hence yielding a sharper endpoint. The iodine will be titrated with a standardized solution of sodium thiosulfate (Na2S2O3).

Why the estimation of copper is known as iodometric titration?

In acid solution practically all oxidizing agents will oxidize iodide ion to iodine quantitatively. The iodine formed in the reaction can then be titrated by means of a standard sodium thiosulfate solution. This type of indirect titration is given the general name of iodometry.

What is difference between iodometric titration and Iodimetric titration?

What is the iodometric determination of copper?

Iodometric determination of copper is based on the oxidation of iodides to iodine by copper (II) ions, which get reduced to Cu +. Comparison of standard potentials for both half reactions (Cu 2+/Cu + E 0=0.17 V, I 2/I – E 0=0.54 V) suggests that it is iodine that should be acting as oxidizer.

What is the purpose of iodometric titration?

Iodometric methods can be used for the quantitative determination of strong oxidizing agents such as potassium dichromate, permanganate, hydrogen peroxide, cupric ion and oxygen. As has been mentioned above, the endpoint in a titration of iodine with thiosulfate is signaled by the color change of the starch indicator.

How to read copper concentration in titration with iodine?

Click Use button. Read number of moles and mass of copper in the titrated sample in the output frame. Click n=CV button in the output frame below copper, enter volume of the pipetted sample, read copper concentration. Apart from general sources of titration errors, when titrating with iodine we should pay special attention to titrant.

How to standardize iodine solution?

The solution is standardized by taking a known amount of oxidizing agent, treating it with excess iodide ion and then titrating the liberated iodine with the solution to be standardized. Oxidizing agents such as potassium dichromate, bromate, iodate or cupric ion can be employed for this procedure.