Understanding Hinsberg's Test
Hinsberg's reagent (benzene sulfonyl chloride, \( C_6H_5SO_2Cl \)) is used to distinguish between primary, secondary, and tertiary amines:
Primary amines react to form sulfonamides, which are soluble in alkali.
Secondary amines react to form sulfonamides that are insoluble in alkali.
Tertiary amines do not react with Hinsberg's reagent.
Analyzing the Given Compounds
The compound containing \( \text{NH}_2 \) group (primary amine) reacts with Hinsberg's reagent.
The compound containing a secondary amine (\( -\text{NH}- \) group) also reacts.
Tertiary amines (\( -\text{N}- \)) do not react with Hinsberg's reagent.
Amides and other compounds that do not contain free primary or secondary amine groups will not react.
Counting the Reactive Compounds
After analyzing the given structures, there are \textbf{5 compounds} containing primary or secondary amines that will react with Hinsberg's reagent.
Conclusion
The number of compounds that give a reaction with Hinsberg's reagent is 5.
Amines have a lone pair of electrons on the nitrogen atom, due to which they behave as Lewis bases. Greater the value of \( K_b \) or smaller the value of \( pK_b \), stronger is the base. Amines are more basic than alcohols, ethers, esters, etc. The basic character of aliphatic amines should increase with the increase of alkyl substitution. However, it does not occur in a regular manner, as a secondary aliphatic amine is unexpectedly more basic than a tertiary amine in aqueous solutions. Aromatic amines are weaker bases than ammonia and aliphatic amines. Electron-releasing groups such as \( -CH_3 \), \( -NH_2 \), etc., increase the basicity, while electron-withdrawing substituents such as \( -NO_2 \), \( -CN \), halogens, etc., decrease the basicity of amines. The effect of these substituents is more pronounced at the para-position than at the meta-position.
(a) Arrange the following in increasing order of their basic character. Give reason:
\[
\includegraphics[width=0.5\linewidth]{ch29i.png}
\]
Find the equivalent capacitance between A and B, where \( C = 16 \, \mu F \).
If the equation of the parabola with vertex \( \left( \frac{3}{2}, 3 \right) \) and the directrix \( x + 2y = 0 \) is \[ ax^2 + b y^2 - cxy - 30x - 60y + 225 = 0, \text{ then } \alpha + \beta + \gamma \text{ is equal to:} \]