The Qualitative Analysis of Ions – Higher Difficulty Problems section is designed to challenge students with complex, multi-step, and reasoning-intensive problems that go beyond standard laboratory identification. This module targets advanced undergraduate learners and competitive exam aspirants, emphasizing deep conceptual application, elimination logic, and equilibrium-based reasoning.
In this section, you will tackle:
Multi-ion identification problems involving overlapping group reactions
Complex equilibrium-based questions using Ksp, common ion effect, and pH variation
Problems involving complex ion formation and decomposition
Redox-driven qualitative reactions with oxidation state analysis
Mixed salt and incomplete data problems requiring logical elimination
Contradictory or misleading observations and their correct interpretation
Stepwise reaction sequence problems with changing reagents
High-level assertion–reason and multi-correct questions
PYQ-inspired advanced problem sets with detailed solutions and reasoning
The content is structured to push analytical limits, strengthen chemical intuition, and prepare students for tough UG exams and high-difficulty competitive questions.
Develop expert-level problem-solving skills in Qualitative Analysis of Ions by mastering advanced and higher-order challenges that demand precision and deep understanding.
Q. In a qualitative analysis using paper chromatography, which factor primarily affects the separation of ions?
A.
Temperature
B.
Solvent polarity
C.
pH of the solution
D.
Ion concentration
Solution
The solvent polarity is the primary factor affecting the separation of ions in paper chromatography, as it influences the interaction between the stationary phase and the ions.
Q. In a qualitative analysis using paper chromatography, which factor primarily affects the Rf value of a substance?
A.
Solvent polarity
B.
Temperature
C.
pH of the solution
D.
Molecular weight
Solution
The Rf value is primarily affected by the polarity of the solvent used in paper chromatography, as it influences the interaction between the stationary phase and the analyte.
Q. In a titration to determine the presence of acetic acid, which indicator would be most appropriate?
A.
Phenolphthalein
B.
Methyl orange
C.
Bromothymol blue
D.
Litmus
Solution
Phenolphthalein is the most appropriate indicator for titrating weak acids like acetic acid against strong bases, as it changes color at the relevant pH range.
Q. In qualitative analysis, what does a positive test for the presence of ammonium ions typically involve?
A.
Formation of a blue complex
B.
Evolution of ammonia gas
C.
Color change with phenolphthalein
D.
Precipitation with barium sulfate
Solution
A positive test for ammonium ions typically involves the evolution of ammonia gas when treated with a strong base, indicating the presence of ammonium.
Q. Which analytical technique is best suited for the qualitative analysis of metal ions in solution?
A.
Mass spectrometry
B.
Infrared spectroscopy
C.
Atomic absorption spectroscopy
D.
Nuclear magnetic resonance
Solution
Atomic absorption spectroscopy is best suited for the qualitative analysis of metal ions, as it allows for the detection of specific metal ions based on their absorption of light.
Correct Answer:
C
— Atomic absorption spectroscopy
Q. Which method is most effective for the qualitative analysis of anions in a mixture?
A.
Titration
B.
Spectrophotometry
C.
Chromatography
D.
Electrophoresis
Solution
Chromatography is the most effective method for the qualitative analysis of anions in a mixture, as it allows for the separation and identification of multiple anions simultaneously.
Q. Which of the following ions would produce a yellow precipitate when treated with silver nitrate?
A.
Chloride
B.
Bromide
C.
Iodide
D.
Sulfate
Solution
Iodide ions produce a yellow precipitate of silver iodide when treated with silver nitrate, while chloride produces a white precipitate and bromide a cream precipitate.
