Introductory investigations: Redox properties

Investigate the redox properties of the unknown.
Choose one of the folowing methods:

A. Reaction with KMnO₄

B. Reaction with KI on filter paper

The unknown is

The unknown

Recall that the solution had no or almost no colour before a few drops of potassium permanganate was added.
The presence of permanganate ions in a solution means that it is red-violet.
If no reaction occurs to reduce permanganate the solution will become coloured by permanganate.

Permanganate is reduced by

Name

Formula

Triiodide is reduced by

Name

Formula

In the KI-paper test, chloride is oxidised by

Name

Formula

Recall that the colourless potassium iodide on a white filterpaper leaves the filterpaper white. If the KI-paper appears brownish this is due to the fact, that iodide has been oxidised to iodine which in aqueous environment appears brownish.

There is no direct contact to the solution in the test tube. Accordingly a reaction resulting in the formation of a gas (which can reach the KI-paper and react with the iodide) must have happened in the test tube.

Consider which gas it could be, and if one of the components in the unknown is oxidising or reducing.

Permanganate is reduced by

Name

Formula

Triiodide is reduced by

Navme

Formula

In the KI-paper test, chloride is oxidised by

Name

Formula