Among the following cations, the number of cations which will give characteristic precipitate in their identification tests with mathrmK_4[mathrmFe(mathrmCN)_6]$\mathrm{K}_4[\mathrm{Fe}(\mathrm{CN})_6]$ is: mathrmCu^2+$\mathrm{Cu}^{2+}$ , mathrmFe^3+$\mathrm{Fe}^{3+}$ , mathrmBa^2+$\mathrm{Ba}^{2+}$ , mathrmCa^2+$\mathrm{Ca}^{2+}$ , mathrmNH_4^+$\mathrm{NH}_4^+$ , mathrmMg^2+$\mathrm{Mg}^{2+}$ , mathrmZn^2+$\mathrm{Zn}^{2+}$

### Related Formula Classification of chromatography based on adsorption vs partition parameters. ### Core Logic Chromatography techniques are broadly divided into two main categories based on their operating principles: 1. **Adsorption Chromatography**: Relies on the differential adsorption of components on the surface of a stationary phase. Both Column Chromatography and Thin Layer Chromatography (TLC) operate on this principle. 2. **Partition Chromatography**: Relies on continuous differential partitioning of components between stationary and mobile liquid phases. Paper Chromatography is a prime example of this category. ### Step 1: Final Selection Thus, statements A and B are correct, matching choice (3). ### Pattern Recognition Remember: Column and Thin Layer chromatography are adsorption-based, while paper chromatography relies on partition mechanisms. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Principles of Practical Chemistry

### Core Logic Let us check the chemical structure of each compound given in the list to determine if it contains a Sulphur (S) atom. 1. **Furan**: A 5-membered heterocyclic aromatic ring containing Oxygen (C_4H_4O$C_4H_4O$). No Sulphur. 2. **Thiophene**: A 5-membered heterocyclic aromatic ring containing Sulphur (C_4H_4S$C_4H_4S$). **Contains Sulphur**. 3. **Pyridine**: A 6-membered heterocyclic aromatic ring containing Nitrogen (C_5H_5N$C_5H_5N$). No Sulphur. 4. **Pyrrole**: A 5-membered heterocyclic aromatic ring containing Nitrogen (C_4H_4NH$C_4H_4NH$). No Sulphur. 5. **Cysteine**: A naturally occurring alpha$\alpha$-amino acid with a thiol side chain (-CH_2-SH$-CH_2-SH$). **Contains Sulphur**. 6. **Tyrosine**: An alpha$\alpha$-amino acid with a phenol side chain. No Sulphur. ### Step 1: Final Count

Only Thiophene and Cysteine contain a sulphur heteroatom. Total number = 2. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Organic Chemistry Some Basic Principles and Techniques Class 12 Chemistry: Biomolecules