The Qualitative Analysis of Ions – Advanced Concepts section explores the theoretical principles and chemical equilibria underlying classical inorganic qualitative analysis. This module is designed for undergraduate Chemistry students and advanced school learners, with emphasis on reaction mechanisms, equilibrium control, and exam-oriented conceptual understanding.
In this section, you will study:
Detailed theory of group separation – role of solubility product (Ksp), common ion effect, and selective precipitation
pH control and buffer action in cation group analysis
Complex ion formation and its role in dissolving precipitates and selective separation
Redox behavior of ions during confirmatory tests
Interfering ions and masking strategies in qualitative analysis
Advanced confirmatory reactions with mechanistic explanations
Thermodynamic and equilibrium considerations in salt analysis
Troubleshooting abnormal observations and mixed-salt scenarios
NCERT- and UG-aligned explanations, supported by reaction mechanisms, equilibrium calculations (introductory), assertion–reason MCQs, and PYQs
The content is structured to strengthen conceptual depth, enhance analytical reasoning, and prepare students for UG examinations, viva voce, and higher-level qualitative analysis questions.
Develop a rigorous understanding of the chemistry behind qualitative analysis to confidently analyze complex inorganic salt systems.
Q. In electrophoresis, what factor primarily influences the migration speed of ions?
A.
Ion concentration
B.
Electric field strength
C.
Temperature of the buffer
D.
Size of the gel pores
Solution
The migration speed of ions in electrophoresis is primarily influenced by the strength of the electric field applied.
Q. In mass spectrometry, what does the term 'fragmentation' refer to?
A.
The separation of ions based on mass
B.
The breaking of molecular bonds to form smaller ions
C.
The ionization of molecules
D.
The detection of ions
Solution
Fragmentation in mass spectrometry refers to the breaking of molecular bonds to form smaller ions, which helps in identifying the structure of the original molecule.
Correct Answer:
B
— The breaking of molecular bonds to form smaller ions
Q. In qualitative ion analysis, what does the term 'selectivity' refer to?
A.
The ability to detect multiple ions
B.
The ability to distinguish between different ions
C.
The speed of analysis
D.
The cost of the analysis
Solution
Selectivity in qualitative ion analysis refers to the ability to distinguish between different ions in a mixture, which is essential for accurate identification.
Correct Answer:
B
— The ability to distinguish between different ions
Q. In UV-Vis spectroscopy, what does a shift in the absorption peak indicate?
A.
Change in concentration
B.
Change in pH
C.
Change in molecular structure
D.
Change in temperature
Solution
A shift in the absorption peak in UV-Vis spectroscopy often indicates a change in molecular structure, such as the formation of new bonds or changes in electronic transitions.
Q. What is the primary purpose of using ion chromatography in qualitative analysis?
A.
To separate ions based on their charge
B.
To identify the presence of specific ions in a mixture
C.
To measure the concentration of ions
D.
To determine the molecular weight of ions
Solution
Ion chromatography is primarily used to identify the presence of specific ions in a mixture by separating them based on their interactions with the stationary phase.
Correct Answer:
B
— To identify the presence of specific ions in a mixture
