JEE MAIN - Chemistry (2003 - No. 22)
Bottles containing C6H5l 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 and C6H5CH2I
B and C6H5I
Addition of HNO3 was unnecessary
A was C6H5I
Uitleg
$${C_6}{H_5}I\,\,\buildrel {NaOH} \over
\longrightarrow \,\,{C_6}{H_5}ONa\,\,\buildrel {HN{O_3}/{H^ + }} \over
\longrightarrow $$
$${C_6}{H_5}OH\,\,\buildrel {AgN{O_3}} \over \longrightarrow \,\,$$ No yellow ppt.
$${C_6}{H_5}C{H_2}I\,\,\buildrel {NaOH} \over \longrightarrow \,\,{C_6}{H_5}C{H_2}ONa\,\,\buildrel {HN{O_3}/{H^ + }} \over \longrightarrow $$
$${C_6}{H_5}C{H_2}OH\,\,\buildrel {AgN{O_3}} \over \longrightarrow .$$ $$\,\,\,$$ yellow ppt.
Since benzyl iodide gives yellow ppt. hence this is compound $$B$$ and $$A$$ was phenyl iodide $$\left( {{C_6}{H_5}I} \right).$$
$${C_6}{H_5}OH\,\,\buildrel {AgN{O_3}} \over \longrightarrow \,\,$$ No yellow ppt.
$${C_6}{H_5}C{H_2}I\,\,\buildrel {NaOH} \over \longrightarrow \,\,{C_6}{H_5}C{H_2}ONa\,\,\buildrel {HN{O_3}/{H^ + }} \over \longrightarrow $$
$${C_6}{H_5}C{H_2}OH\,\,\buildrel {AgN{O_3}} \over \longrightarrow .$$ $$\,\,\,$$ yellow ppt.
Since benzyl iodide gives yellow ppt. hence this is compound $$B$$ and $$A$$ was phenyl iodide $$\left( {{C_6}{H_5}I} \right).$$