Question

One mole of an ideal gas at 350K is in a 2.0 L vessel of thermally conducting walls, which are in contact with the surroundings. It undergoes isothermal reversible expansion from 2.0L to 3.0L against a constant pressure of 4 atm. The change in entropy of the surroundings (ΔS) is JK (Nearest integer) Given: R = 8.314 J K^-1 Mol^-1.

Answer 1

Correct Answer: 3

Given the reaction of N,N-dimethylaniline ('A') with NaNO2 and HX to form 'B', the correct statements are: (1) The electrophile involved in the reaction is NO+. (3) The reaction occurs at low temperature. (4) The product 'B' formed in the above reaction is p-nitroso compound at low temperature. 

Explanation: The reaction is a diazotization reaction specific to tertiary aromatic amines. NaNO2 and HX generate the nitrosonium ion (NO+), which is the electrophile. Diazotization reactions are performed at low temperatures to prevent decomposition of intermediates. The product formed is a p-nitroso compound due to electrophilic aromatic substitution at the para position. Statement (2) is incorrect because the product is a p-nitroso compound, not an N-nitroso ammonium compound.