question_answer

The oxidation number of chromium in\[Cr{{O}_{5}}\]is

A)  +3                                         

B)  + 5

C)  + 10                      

D)         + 6

Correct Answer: D

Solution :

The structure of\[Cr{{O}_{5}}\]is as The structure shows that four oxygen atom in\[Cr{{O}_{5}}\]are involve in the formation of peroxide linkage (OS of oxygen = -1) while one is present as oxide (OS of oxygen = -2). Therefore, \[Cr{{O}_{5}}\]                 \[\underset{for\,\,Cr}{\mathop{x}}\,+1\times \underset{for\,\,O}{\mathop{(-2)}}\,+4\underset{for\,\,(O-O)}{\mathop{(-1)=0}}\,\]                 \[x-2-4=0\]                 \[x=\pm 6\]