The delocalisation of $\sigma$ electrons of C-H bond of an alkyl group with the $\pi$ electrons of benzene is observed in

An alkene $X\left(\mathrm{C}_6 \mathrm{H}_{12}\right)$ on ozonolysis gave acetaldehyde and ethyl methyl ketone. What is the product formed when $X$ reacts with HBr ?

$$ \text { What is } X \text { in the following reaction sequence? } $$

A compound is formed by elements $A, B$ and O . Atoms of oxygen form ccp lattice. Atoms of $A$ (cation) occupy $\frac{1}{8}$ th of tetrahedral voids and atoms of $B$ (cation) occupy half of octahedral voids. What is the molecular formula of the compound?