Question

For chemicals below:

NaBiO3, Br2, Vitamin C, FeSO4, Na2C2O4, KBrO3, I2, SnCl2, Na2S2O3, As2O3, KIO3, K2Cr2O7, KMnO4, Ce(SO4)2, Starch

a) Which are oxidizing agents?
b) Which are reducing agents?
c) Which can be used as primary standards?

Answer 1

a) Oxidizing agents:

You can look at the oxidation state of the metal and see if it can act as an oxidizing agent or reducing agent. For e.g. In the oxidation state of Cr is +6. Hence, it can itself get reduced to +4 or +5 and thereby oxidizing another species.

The chemicals that itself gets reduced in the process of oxidizing another substance. Among the given substances, the following are oxidizing agents.

b) Reducing agents are  the substances that itself can get oxidise and in the process reduce the other species in the reaction. The following are reducing agents from the list.

c) Primary standards are substance which are very pure and thus when we make a solution by taking them in a solvent, we can accurately determine its concentration. Generally the substance that do not make hydrated complexes and goes not get easily oxidised are taken as primary standards. Among the given substances, the following can be used as a primary standard: