





Which of the following are aromatic?

Give plausible explanation for:
(a) Diazonium salts of aromatic amines are stable.
(b) Aniline does not undergo Friedel-Crafts reaction.
(c) Aniline on nitration gives substantial meta product.
Consider the following two reactions A and B: 
The numerical value of [molar mass of $x$ + molar mass of $y$] is ___.
Consider an A.P. $a_1,a_2,\ldots,a_n$; $a_1>0$. If $a_2-a_1=-\dfrac{3}{4}$, $a_n=\dfrac{1}{4}a_1$, and \[ \sum_{i=1}^{n} a_i=\frac{525}{2}, \] then $\sum_{i=1}^{17} a_i$ is equal to
