Applications - Analytical, Biological, Industrial - UNSOLVED PRACTICE SET

Q7. How is the complex formation used in the separation of Ag⁺ and Hg²⁺ in qualitative analysis? Explain.

Q8. What is the role of haemoglobin in the human body? Write the equation for the reversible binding of oxygen.

Q9. Why is cis-[Pt(NH₃)₂Cl₂] effective as an anti-cancer drug while the trans isomer is not? (Explain the key structural reason.)

Q10. How is EDTA used in the estimation of hardness of water? Write the reaction involved.

Q11. What is the role of chlorophyll in photosynthesis? Which metal ion is present at the centre of the chlorophyll molecule?

Q12. Name one industrial application of coordination compounds as catalysts. Write the reaction catalyzed.

Q13. Discuss the biological applications of coordination compounds. Explain the role of:

(a) Haemoglobin in oxygen transport

(b) Chlorophyll in photosynthesis

(c) Vitamin B₁₂ (cyanocobalamin) in the human body

Q14. (a) Explain how coordination compounds are used in qualitative and quantitative analysis. Give examples of:

(i) Detection of metal ions using complex formation

(ii) Masking of interfering ions

(iii) EDTA titrations

(b) Why is dimethylglyoxime (DMG) used as a specific reagent for nickel(II) ions?

Q15. (a) Discuss the medicinal applications of coordination compounds. Explain the role of:

(i) Cis-platin as an anti-cancer drug

(ii) EDTA in treating lead poisoning

(iii) Gold complexes in treating rheumatoid arthritis

(b) Why are the geometry and isomerism of cis-platin important for its biological activity?

Q16. In a qualitative analysis lab, a student is given an unknown solution containing a mixture of Cu²⁺, Fe³⁺, and Ni²⁺ ions.

(a) How can the student separate and identify Cu²⁺ using complex formation? (Name the reagent and the colour of the complex formed.)

(b) How can Fe³⁺ be detected using thiocyanate ions? Write the reaction and describe the colour change.

(c) How can Ni²⁺ be confirmed using dimethylglyoxime (DMG)? Describe the appearance of the precipitate.

(d) If excess NH₃ is added to the mixture, which ions will form stable ammine complexes? Write the formulae of these complexes.

(e) Explain how the formation of these complexes helps in the separation of metal ions during qualitative analysis.

Q17. The water supply in a small town in India has a hardness of 300 ppm (as CaCO₃). The municipal corporation decides to use the EDTA method to measure and control hardness.

(a) Write the chemical reaction between Ca²⁺ ions and EDTA (represented as H₂Y²⁻ for simplicity).

(b) If 50 mL of water sample requires 15 mL of 0.01 M EDTA solution for titration, calculate the hardness of water in ppm of CaCO₃.

(c) Why is a buffer solution of pH ≈ 10 used in this titration?

(d) The indicator used is Eriochrome Black T (EBT). Explain how it works in this titration. (Describe the colour changes.)

(e) If the water also contains Mg²⁺, will the EDTA titration give the total hardness or only calcium hardness? Explain.

Q18. In a hospital in Delhi, a cancer patient is being treated with cis-platin (cis-[Pt(NH₃)₂Cl₂]). The doctor explains that this drug works by binding to DNA in cancer cells.

(a) Draw the structure of cis-platin and label the important features.

(b) Explain why the cis isomer is biologically active while the trans isomer is not. (Consider the geometry and how it interacts with DNA.)

(c) The drug is administered intravenously. Why can't it be given orally?

(d) One side effect of cis-platin is kidney damage. How is this managed clinically?

(e) Research is ongoing on "second-generation" platinum drugs like carboplatin and oxaliplatin. What advantage do these have over cis-platin? (General comparison only.)