To determine the basic strength of the given molecules, we need to consider the electron-donating and electron-withdrawing effects of substituents on the phenyl group.
- (A): \(\text{C}_6\text{H}_4\text{NH}_2\text{O}\) (Hydroxyl group is an electron-donating group, which increases the basicity of the amine group.)
- (B): \(\text{C}_6\text{H}_4\text{NH}_2\text{MeO}\) (Methoxy group is a strong electron-donating group, which further increases the basicity of the amine group.)
- (C): \(\text{C}_6\text{H}_4\text{NH}_2\text{NO}_2\) (Nitro group is a strong electron-withdrawing group, which decreases the basicity of the amine group.)
- (D): \(\text{C}_6\text{H}_4\text{NH}_2\text{CH}_3\) (Methyl group is a weak electron-donating group, but its effect is weaker than the hydroxyl or methoxy group.) The order of basic strength is determined by the electron-donating ability of the substituent groups. Therefore, the order is: \[ \text{B}>\text{A}>\text{D}>\text{C} \] Thus, the correct order is \( B>A>C>D \), which corresponds to option (4).
A substance 'X' (1.5 g) dissolved in 150 g of a solvent 'Y' (molar mass = 300 g mol$^{-1}$) led to an elevation of the boiling point by 0.5 K. The relative lowering in the vapour pressure of the solvent 'Y' is $____________ \(\times 10^{-2}\). (nearest integer)
[Given : $K_{b}$ of the solvent = 5.0 K kg mol$^{-1}$]
Assume the solution to be dilute and no association or dissociation of X takes place in solution.
Inductance of a coil with \(10^4\) turns is \(10\,\text{mH}\) and it is connected to a DC source of \(10\,\text{V}\) with internal resistance \(10\,\Omega\). The energy density in the inductor when the current reaches \( \left(\frac{1}{e}\right) \) of its maximum value is \[ \alpha \pi \times \frac{1}{e^2}\ \text{J m}^{-3}. \] The value of \( \alpha \) is _________.
\[ (\mu_0 = 4\pi \times 10^{-7}\ \text{TmA}^{-1}) \]