Question

Question No. 30
• Aniline shows wavelength of
maximum absorption at 280 nm,
whereas Anilium ion (Acidic solution
of Aniline) show wavelength of
maximum absorption at 254 nm this
is an example of shift​

Answer 1

Explanation:

• The most precise spectrophotometric method for the determination of aniline in water is by coupling aniline with diazotizedp-nitroaniline in the presence of ethanol and sodium hydroxide
• To form an intense red water-soluble azo-dye which shows maximum absorption at 505 nm and greater stability and sensitivity in the presence of cetyltrimethylammonium bromide.
• Beer's law is obeyed over the aniline concentration range 0.2–2.4μg/ml in the solution measured.
• The molar absorptivity is 3.46×104l· mole−1·cm−1, and the relative standard deviation 1–2%, depending on the aniline concentration.
• Aniline in basic medium exists as free form PhNH2 whereas in acidic medium aniline is converted to anilinium salt (PhNH3 +).