Question

Match List I (Aqueous solubility) with List II (Drugs with melting points): [H] {|l|l|l|l|} \multicolumn{2}{|c|}{LIST-I & \multicolumn{2}{c|}{LIST-II
\multicolumn{2}{|c|}{(Aqueous solubility (moles/ liter $\times$ 10$^2$) in water at 30$^\circ$C) & \multicolumn{2}{c|}{(Drugs with melting points in $^\circ$C)
A. & 4.5 & I. & 7-Propyl theophylline (99-100)
B. & 13.3 & II. & Caffeine (238)
C. & 17.6 & III. & Theophylline (270-274)
D. & 104 & IV. & 7-Ethyl theophylline (156-157)

• A. A-III, B-IV, C-II, D-I
• B. A-III, B-I, C-IV, D-II
• C. A-I, B-II, C-IV, D-III
• D. A-III, B-II, C-IV, D-I

Hint:

Higher Melting Point $\rightarrow$ Lower Solubility.

Answer 1

The Correct Option is D

Step 1: Concept
There is generally an inverse relationship between a drug's melting point and its aqueous solubility.

Step 2: Meaning
High melting points indicate strong intermolecular forces, often leading to lower solubility.

Step 3: Analysis
Theophylline ($270$-$274^{\circ}C$) has the highest MP and lowest solubility (4.5). Caffeine ($238^{\circ}C$) follows with solubility 13.3. 7-Ethyl theophylline ($156$-$157^{\circ}C$) matches 17.6. 7-Propyl theophylline ($99$-$100^{\circ}C$) has the lowest MP and highest solubility (104).

Step 4: Conclusion
The correct matches are: A-III, B-II, C-IV, D-I.

Final Answer: (D)