Question

The structure of PCC is:
(A) C$_6$H$_5$N$^{+}$HCrO$_2$Cl$^{-}$
(B) C$_6$H$_5$N$^{+}$HCrO$_3$Cl$^{-}$
(C) C$_5$H$_5$N$^{+}$HCrO$_2$Cl$^{-}$
(D) C$_5$H$_5$N$^{+}$HCrO$_3$Cl$^{-}$

Answer 1

Hint: By knowing the chemical name of PCC, the structure of PCC can be identified. PCC is an organic compound known to be Pyridinium Chlorochromate. From the name we can say there is a pyridine molecule having chlorine and chromate ions.

Complete step by step answer:
-Firstly, we know PCC is pyridinium chlorochromate. So, firstly we will see the it has chemical formula C$_5$H$_5$N, but in the PCC pyridine acts as pyridinium ion C$_5$H$_5$N$^{+}$H. The structure of the pyridine is given below-

-Now, the next is chlorochromate, and its chemical formula is [CrO$_3$Cl$^{-}$] and its structure is given below-

-By combining all these structures, we get the following structure-
.
-In this structure we can see that the chromate ion is surrounded by the chlorine atom, and the three oxygen atoms but the valency of one oxygen atom is not completed.

-Now, we will write the chemical formula by seeing the structure. Thus, the chemical formula of PCC is C$_5$H$_5$N$^{+}$H[CrO$_3$Cl$^{-}$]. The correct option is D.

Additional information: PCC is a yellow-orange salt reagent, used primarily for the oxidation of alcohols to form carbonyls. It is selective towards the oxidation of alcohols to aldehydes, or ketones, while some are less selective.

Note: Don’t get confused between the charges mentioned in the structure. The structure of pyridinium ion and anilinium ion. Both are different compounds related to the benzene. The former one represents C$_5$H$_5$N$^{+}$H and the latter one represents C$_6$H$_5$NH$_3$$^{+}$.