X is phenol, formed when benzenediazonium chloride is hydrolysed by water at 283 K.C6​H5​N2​Cl+H2​O283 K​C6​H5​OH+N2​+HClWhen phenol is treated with concentrated HNO3​, nitration occurs at the ortho and para positions to give 2,4,6-trinitrophenol, i.e. picric acid.C6​H5​OH+3HNO3​→2,4,6-(NO2​)3​C6​H2​OH+3H2​OSo Y is picric acid (2,4,6-trinitrophenol).When phenol is treated with bromine water, electrophilic bromination at the ortho and para positions gives a white precipitate of 2,4,6-tribromophenol.C6​H5​OH+3Br2​→2,4,6-Br3​C6​H2​OH+3HBrSo Z is 2,4,6-tribromophenol.Hence Y and Z respectively are picric acid (2,4,6-trinitrophenol) and 2,4,6-tribromophenol.Therefore the correct option is the one listing picric acid and 2,4,6-tribromophenol.
