Question

The equivalent weight of potassium dichromate in acidic medium is:

Answer 1

We know that, equivalent weight (also referred to as gramme equivalent) is the mass of an equivalent, the mass of a substance to be combined with, or replaced by, another substance's fixed volume. Unlike molecular weight, the weight equivalent is the relative mass of chemical entities that integrate or displace other chemical entities. Equal Weight. It is referred to as the mass of an element/compound/ion that blends or displaces one part of hydrogen or eight parts of oxygen or chlorine by mass.

Complete step by step answer:
Potassium Dichromate is an orange to red, crystalline, inorganic compound that releases poisonous chromium fumes upon heating. Potassium dichromate is extremely corrosive and is a heavy oxidising agent.
The responses. Potassium dichromate is an oxidising agent and is milder than potassium permanganate in organic chemistry. It is used to oxidise alcohol. Under more forceful conditions, it converts primary alcohols into aldehydes and into carboxylic acids.
Acidified potassium dichromate is an oxidising agent which oxidises primary alcohols, secondary alcohols and aldehydes (VI). During oxidation, dichromate (VI) ions are reduced, and the colour changes from orange to green.
Potassium dichromate in an acidic medium is a strong oxidizer. It means it gains electrons during redox reaction. Potassium dichromate in acidic solution results in the following reaction:
${K_2}C{r_2}{O_7} + 14H + 6{e^ - } \to 2K + 2C{r_3} + 7{H_2}O$
There is overall gain of six electrons.
We know the formula of equivalent weight. It is given by,
$\dfrac{{Molecular{\text{ }}weight}}{n}$
where n is the factor of the equation.
Molecular weight of potassium dichromate is =$294$ g/mol
Since, the overall gain of electrons is $6$.
Thus, n =$6$
$\therefore equivalent{\text{ }}weight = \dfrac{{294}}{6} = 49g/mol$

Hence, the correct answer is 49g/mol.

Note: We must remember that the acidified potassium dichromate solution is an orange solution which, when the alcohol is oxidised, changes to green. This can be used as an alcohol measure, and only alcohols with acidified potassium dichromate solution show the orange to green colour change. As the rare mineral lopezite, potassium dichromate occurs naturally. It was only reported as vug fillings in the nitrate deposits of the Chilean Atacama Desert and in the South African Bushveld Igneous Complex.