Question

Match the LIST-I with LIST-II 

LIST-I		LIST-II
(Diffusion Coefficients of Gases in Water at 20°C)		D (\(10^{-9}\) m\(^2\) s\(^{-1}\))
A	Chlorine	I	2.1
B	Carbon dioxide	II	1.9
C	Nitrogen	III	1.6
D	Oxygen	IV	1.8

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

Hint:

To estimate relative diffusion coefficients, first consider molecular size (smaller is faster). Heavier or larger molecules like chlorine will diffuse slower than smaller ones like oxygen and nitrogen.

Answer 1

The Correct Option is B

Step 1: Understand the factors affecting the diffusion coefficient. Generally, smaller molecules diffuse faster. However, chemical interactions with the solvent (water) also play a role.
Step 2: Analyze the molecules.
Chlorine (Cl$_2$): Molar mass approx 71 g/mol. It is the largest molecule. It should have the lowest diffusion coefficient. Matching A with III (1.6) is logical.
Oxygen (O$_2$): Molar mass approx 32 g/mol. It is a small, non-polar molecule. It is known to diffuse relatively fast in water. Matching D with I (2.1) is a good fit.
Nitrogen (N$_2$): Molar mass approx 28 g/mol. Similar in size to oxygen but slightly smaller. Its diffusion coefficient should be high, similar to oxygen.
Carbon dioxide (CO$_2$): Molar mass approx 44 g/mol. It is larger than N$_2$ and O$_2$.

Step 3: Match the remaining gases. We have B (CO$_2$) and C (N$_2$) to match with II (1.9) and IV (1.8). Given their properties, it is reasonable to assign B (CO$_2$) to II (1.9) and C (N$_2$) to IV (1.8).
This gives the complete matching: A-III, B-II, C-IV, D-I.