
In basic or neutral medium \(N-N\) coupling favourable while in slightly acidic medium \(C- N\) coupling favourable.
So, the correct option is (B): \(B\) only.

Statement I: Primary aliphatic amines react with HNO2 to give unstable diazonium salts.
Statement II: Primary aromatic amines react with HNO2 to form diazonium salts which are stable even above 300 K.
Choose the most appropriate answer from the options given below:
Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion : tert-Butyl amine can be formed by Gabriel phthalimide synthesis.
Reason : It follows \(SN_1\) mechanism.
In the light of the above statements, choose the correct answer from the options given below
Consider the sound wave travelling in ideal gases of $\mathrm{He}, \mathrm{CH}_{4}$, and $\mathrm{CO}_{2}$. All the gases have the same ratio $\frac{\mathrm{P}}{\rho}$, where P is the pressure and $\rho$ is the density. The ratio of the speed of sound through the gases $\mathrm{v}_{\mathrm{He}}: \mathrm{v}_{\mathrm{CH}_{4}}: \mathrm{v}_{\mathrm{CO}_{2}}$ is given by