Question

The surface tension of which of the following liquid is maximum

• A. H₂O
• B. C₆H₆
• C. CH₃OH
• D. C₂H₅OH

Answer 1

The Correct Option is A

In this question, we are asked to determine which of the given liquids has the maximum surface tension. The options are H₂O (water), C₆H₆ (benzene), CH₃OH (methanol), and C₂H₅OH (ethanol). Let's evaluate the surface tension of each:

1. Water (H₂O): Water is known to have a high surface tension due to its hydrogen bonding. The polar nature and extensive hydrogen bonding among water molecules result in a relatively strong cohesive force at the surface.
2. Benzene (C₆H₆): Benzene has a lower surface tension compared to water because it lacks hydrogen bonding and has weaker van der Waals interactions.
3. Methanol (CH₃OH): Methanol can hydrogen bond similar to water but with less extent due to its smaller size and presence of only one -OH group, leading to a lower surface tension than that of water.
4. Ethanol (C₂H₅OH): Ethanol, like methanol, exhibits hydrogen bonding; however, the presence of the ethyl group makes it less effective in hydrogen bonding compared to water, thus resulting in lower surface tension.

From these assessments, it is evident that water (H₂O) has the maximum surface tension among the given options due to the strong hydrogen bonding between its molecules.

Conclusion: The surface tension of H₂O is maximum, making option H₂O the correct answer.