question_answer

 A, B and C respectively are:

A) \[{{K}_{2}}S{{O}_{4}}\],\[{{K}_{2}}Cr{{O}_{4}}\]and \[{{K}_{2}}C{{r}_{2}}{{O}_{7}}\]

B) \[{{K}_{2}}S{{O}_{4}}\],\[N{{a}_{2}}Cr{{O}_{4}}\] and \[N{{a}_{2}}C{{r}_{2}}{{O}_{7}}\]

C) \[{{H}_{2}}S{{O}_{4}}\],\[NaCr{{O}_{2}}\] and \[{{K}_{2}}C{{r}_{2}}{{O}_{7}}\]

D) \[{{H}_{2}}S{{O}_{4}}\],\[N{{a}_{2}}C{{r}_{2}}{{O}_{7}}\] and \[{{K}_{2}}C{{r}_{2}}{{0}_{7}}\]

Correct Answer: D

Solution :

[d] This reaction is the method of preparation of \[{{K}_{2}}C{{r}_{2}}{{O}_{7.}}\]