Question

What is the action of heat on ${{\text{K}}_{\text{2}}}{\text{C}}{{\text{r}}_{\text{2}}}{{\text{O}}_{\text{7}}}$?

Answer 1

Hint: We know that the compound potassium dichromate (${{\text{K}}_{\text{2}}}{\text{C}}{{\text{r}}_{\text{2}}}{{\text{O}}_{\text{7}}}$) is an inorganic chemical compound which has a wide industrial and laboratory uses. It is an orange coloured compound and has a strong oxidising power.

Complete step by step answer:
We know that some compounds will decompose on the action of heat. Similarly, the potassium dichromate also decomposes to give potassium chromate (${{\text{K}}_{\text{2}}}{\text{Cr}}{{\text{O}}_{\text{4}}}$) and ${{\text{O}}_{\text{2}}}$ is evolved. The reaction of the decomposition of potassium dichromate is as follows:
\[4{K_2}C{r_2}{O_7} \to 4{K_2}Cr{O_4} + 2C{r_2}{O_3} + 3{O_2}\]
So, the action of heat on potassium dichromate will decompose it to give potassium chromate and oxygen gas will be evolved.

Additional Information:
 Let us have a look through the importance and the uses of potassium dichromate:
Potassium dichromate is an odourless compound.
The potassium dichromate is insoluble in acetone and alcohol while it is soluble in the water.
Potassium dichromate is widely in leather tanning and also it is a precursor to potassium chrome alum.
Potassium dichromate is a common oxidizing agent which is widely used in industries and laboratories.
Potassium dichromate can be prepared by reacting potassium chloride on sodium dichromate.
Potassium dichromate is also prepared from potassium chromate by the roasting of chromite ore with potassium hydroxide.

Note: We may be familiar that the potassium dichromate is used in photographic screen printing. We can use the potassium dichromate as a stain for some types of woods to produce deep rich browns. Also, potassium dichromate has many medicinal uses like antiseptic.