AIEEE 2013 PYQ Mock Test

Which of the following exists as covalent crystals in the solid state?

Compound (A), ${\text{C}}_8{\text{H}}_9\text{Br}$, gives a white precipitate when warmed with alcoholic ${\text{AgNO}}_3$. Oxidation of (A) gives an acid (B), ${\text{C}}_8{\text{H}}_6{\text{O}}_4$. (B) easily forms anhydride on heating. Identify the compound (A).

Energy of an electron is given by $E=-2.178\times 10^{-18}\frac{Z^2}{n^2}\text{J}$. Wavelength of light required to excite an electron in a hydrogen atom from level $n=1$ to $n=2$ will be ($h=6.62\times 10^{-34}\text{Js}$ and $c=3.0\times 10^8{\text{ms}}^{-1}$):

An organic compound A upon reacting with ${\text{NH}}_3$ gives B. On heating B gives C. C in presence of $\text{KOH}$ reacts with ${\text{Br}}_2$ to give ${\text{CH}}_3{\text{CH}}_2{\text{NH}}_2$. A is:

In which of the following pairs of molecules/ions, both the species are not likely to exist?