Question

One mole of acidified ${K_2}C{r_2}{O_7}$ on reaction with excess of KI will liberate moles of ${I_2}$.
a.) 6
b.) 1
c.) 7
d.) 3

Answer 1

Hint: Potassium dichromate, ${K_2}C{r_2}{O_7}$ is a popular inorganic chemical reagent used in a number of laboratory and industrial applications as oxidants. This is transient and permanently detrimental to wellbeing, as in other hexavalent chromium compounds. It's a really white, red-orange, crystalline ionic solid. In the lab the salt is common since it is not deliquescent, as compared to salt dichromate, which is more industry-relevant.

Complete step-by-step answer:
An oxidizing agent is in one sense a chemical species which is subjected to a chemical reaction in which one or more electrons are formed. In this way, it is one part of a redox reaction. The second is that an oxidizing agent is a chemical substance that moves electron-negative atoms through a substratum, normally oxygen. Oxidation, explosives and chemical redox reactions are used in radioactive reactions.
As given in the question, when one mole of acidified ${K_2}C{r_2}{O_7}$ reacts in the presence of excess of KI, it will give some moles of ${I_2}$. This is only possible because ${K_2}C{r_2}{O_7}$ is an oxidizing agent. It will oxidize ${I^ - }$ to ${I_2}$ immediately and will get reduced itself.
The reaction will go like this-
$ \Rightarrow {K_2}C{r_2}{O_7} + 7{H_2}S{O_4} + 6KI = 4{K_2}S{O_4} + C{r_2}{\left( {S{O_4}} \right)_3} + 7{H_2}O + 3{I_2}$
As we can see from the above reaction that one mole of ${K_2}C{r_2}{O_7}$ gave exactly 3 moles of ${I_2}$ on reaction with excess of KI.

Hence, option D is the correct option.
The organic element, drug and nutritional supplement is potassium iodide. A medicine used in radiation emergencies for combating hyperthyroidism and shielding the thyroid gland while other kinds of radiopharmaceuticals are used. Skin sporotrichosis and phycomycosis were also seen in the developed world. This is seen in individuals with insufficient amounts of iodine in their food as a substitute. The mouth offers it.

Note: An oxidizing agent is a chemical (oxidant and oxidizer) material capable of oxidizing certain compounds, i.e. of consuming their electrons. Oxygen, hydrogen peroxide and halogens can each be classified as an oxidant.