question_answer

Concentrated sulphuric acid can be reduced by

A)  \[NaCl\]                             

B)  \[NaF\]

C)  \[NaOH\]                           

D)  \[NaN{{O}_{3}}\]

E)  \[NaBr\]

Correct Answer: E

Solution :

                Concentrated sulphuric acid, being a strong acid, oxidises bromides and iodides but not chlorides and fluorides since, the latter are more electronegative. Hence, it, can be reduced by only\[NaBr\]among the given options. \[\overset{+\,6}{\mathop{{{H}_{2}}S{{O}_{4}}}}\,+\overset{-1}{\mathop{NaBr}}\,\xrightarrow{{}}\overset{+\,6}{\mathop{NaHS{{O}_{4}}}}\,+\overset{-1}{\mathop{HBr}}\,\]