Which method cannot be used to estimate nitrogen in compounds containing nitro groups?
Kjeldahl’s method fails for nitro compounds (-NO₂) as nitrogen is not easily converted to NH₃; Dumas method is preferred.
Ref: NCERT Class 11 Chemistry > Chapter 8: Organic Chemistry - Some Basic Principles and Techniques > Topic: Qualitative and Quantitative Analysis - Lassaigne Test and Estimation