4 public questions tagged with this topic.
In Kjeldahl’s method, nitrogen is converted to NH₃ (ammonia), which is then titrated with acid.
Ref: NCERT Class 11 Chemistry > Chapter 8: Organic Chemistry - Some Basic Principles and Techniques > Topic: Qualitative and Quantitative Analysis - Lassaigne Test and Estimation
Moles of H₂SO₄ = 0.015 × 0.2 = 0.003. Moles of NH₃ = 0.006 (2H per H₂SO₄). Mass of N = 0.006 × 14 = 0.084 g. Percentage = (0.084/0.42) × 100 = 20%.
Ref: NCERT Class 11 Chemistry > Chapter 8: Organic Chemistry - Some Basic Principles and Techniques > Topic: Isomerism - Stereoisomerism - Geometrical and Optical Isomerism
Total volume = 4V, HZ initial = 0.06 × 4V = 0.08 M × 3V , NaOH = 0.02V , [Z-] = (0.02V/4V) = 0.005 M . pH = 4.5 + log (0.005/0.06) = 4.5 - 1.08 = 3.42 .
Ref: NCERT Class 11 Chemistry > Chapter 6: Equilibrium > Topic: Ionic Equilibrium - Acids Bases and pH and Ionization of Weak Acids Bases
It becomes negatively charged correctly describes the effect or change asked about in this question. In Titration of Amino Acids, understanding cause-and-effect relationships is essential for predicting biological outcomes. It becomes negatively charged occurs because of specific molecular interactions, thermodynamic principles, or regulatory mechanisms that govern this biological process. The other options (It becomes positively charged, It remains neutral, and It precipitates) describe either opposite effects, effects that occur under different conditions, or changes associated with unrelated processes.
Ref: Lehninger Principles of Biochemistry, Nelson & Cox, 8th Ed., Ch. 3
