In which of the following sets, all the given species are isostructural?
CO2, NO2, ClO2, SiO2
PCl3, Al Cl3, BCl3, SbCl3
BF3, NF3, PF3, Al F3
BF-4 ,CCl4 ,NH+4 , PCl+4
Isostructural species are the molecules that have the same shape and also the same connectivity. In the question, BF4- ,CCl4 ,NH4+ , PCl4+ are isostructural because they have tetrahedral structure. The atoms occupy one of the vertices of the tetrahedron around the central atom.
Name the products formed when phenol is treated with the following reagents:
(i) Bromine water
(ii) Zinc dust
(iii) Conc. HNO_3
(i) Predict the products A and B in the hydroboration-oxidation reaction.
(ii) Explain the preparation of phenol from cumene.
From the following, how many compounds contain at least one secondary alcohol? 
Given below are two statements:
Statement I: Transfer RNAs and ribosomal RNA do not interact with mRNA.
Statement II: RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defence.
In the light of the above statements, choose the most appropriate answer from the options given below: