Account for the yellow color that appears in concentrated nitric acid when it is left standing in an ordinary glass bottle?
Explain why
(a) Only all-glass apparatus should be used for the preparation of nitric acid by heating concentrated sulphuric acid and potassium nitrate.
(b) Nitric acid is kept in a reagent bottle for a long time.
Explain the following:
Concentrated nitric acid appears yellow when it is left standing in a glass bottle.