Question

Bottles containing C₆H₅I and C₆H₅CH₂I lost their original labels. They were labelled A and B for testing. A and B were separately taken in test tubes and boiled with NaOH solution. The end solution in each tube was made acidic with dilute HNO₃ and then some AgNO₃ solution was added. Substance B gave a yellow precipitate. Which one of the following statements is true for this experiment? 

(a) A was C₆H₅I 

(b) A was C₆H₅CH₂I

(c) B was C₆H₅I

(d) Addition of HNO₃ was unnecessary

Answer 1

(a) A was C₆H₅I 

\(C_6H_5I \xrightarrow[boil]{aq.NaOH}No\,reaction\)

\(\xrightarrow[AgNO_3]{dil.HNO_3}NO\,reaction\)

\(C_6H_5CH_2I \xrightarrow[boil]{aq.NaOH}C_6H_5CH_2OH+NaI\)

\(\xrightarrow[AgNO_3]{dil.HNO_3} \underset{(yellow\,ppt)}{AgI\,\downarrow}\)

So B is C₆H₅CH₂I, hence A is C₆H₅I