Ncert Solutions Chemistry Class 12th

During nitration of aniline, meta product is also formed, it is because of due to presence of anilinium ion. In anilium $-\stackrel{+}{N}{H}_3$ group is meta directing group.

2, 4-DNP (Brady's Reagent) is used to test carbonyl compound

(a) Na₂CO₃ -> Solvay

(b) Ti -> Van-Arkel

(c) Cl₂ -> Deacon

(d) NaOH -> Castner – kellner

Kindly consider the following figure

A > B > C > D

Lone pair is localized in (A) while all 3 have delocalized lone pair but they can be compared by 3° > 2° > 1° because methyl group increases the basicity.

S > O > Se > Te   

Leaching of Al₂O₃ with alkali;

$\begin{array}{l}A{l}_2{O}_3\left(s\right)+2NaOH\left(aq\right)+3H_{2}O\left(l\right)\to 2Na\left[Al{\left(OH\right)}_4\right]\left(aq\right)\\ X\end{array}$            

$\begin{array}{l}2Na\left[Al{\left(OH\right)}_4\right]\left(aq\right)+2C{O}_2\left(g\right)\to A{l}_2{O}_3.x{H}_{2}O\left(s\right)+2NaHC{O}_3\left(aq\right)\\ XYZ\end{array}$

Both (A) and (B) are correct but R is not correct explanation of A. In both $T\mathcal{l}{l}_{3}andCs{l}_3$ oxidation state of metal is +1, also both have similar lattice structure.   $T\mathcal{l}=4f^{14}5d^{10}6s^{2}6p^1$