`aK_(2)Cr_(2)O_(7)+bKCl+cH_(2)SO_(4)rarrxCrO_(2)Cl_(2)+yKHSO_(4)+zH_(2)O`
The above equation balances when

Options

A. ` a=4, b=2, c=6` and `x=6, y=2, z=3`
B. ` a=6, b=4, c=2` and `x=6, y=3, z=2`
C. ` a=1, b=4, c=6` and `x=2, y=6, z=3`
D. `a=2,b=4, c=6` and `x=2, y=6 , z=2`

Answer

C

Explanation

Note that one formula unit of ` K_2Cr_2O_7` contains two Cr atoms. Thus, To balance the number fo Cr atoms on both sides, we sholud have ` x=2` and `a=1`. Thus , option (3) is correct. Also note that this is not a redox reaction as there is no change in the oxidation number of any given element. The formation fo ` CrO_2 Cl_2` cna be described as follows :
`{:(K_(2)Cr_(2)O_(7)+2H_(2)SO_(4) rarr2KHSO_(4)+2CrO_(3)+H_(2)O),(2KCl+H_(2)SO_(4) rarr 2KHSO_(4)+2HICl"]"xx2),(CrO_(3)+2HCl rarr CrO_(2)Cl_(2)+H_(2)O"]"xx2),(bar(K_(2)Cr_(2)O_(7)+4HCl+6H_(2)SO_(4) rarr 2CrO_(2)Cl_(2)+6KHSO_(4)+3H_(2)O)):}`