Question #bd770

Sep 9, 2017

Water

Explanation:

Here are the surface tension of the liquids at ${20}^{o}$(constant temprature) with Air :-

• Methanol - 22.5 mN·m−1
• Ethanol - 22.39 mN·m−1
• Water - 72.86 mN·m−1
• Benzene - 28.88 mN·m−1

(All units in milli Newton per Metre - $\frac{m N}{m}$)

Why? Be cause the water molecules attract one another due to the water's polar property. The hydrogen ends, which are positive in comparison to the negative ends of the oxygen cause water to " stick " together. Non-polar molecules like Benzene have a lower surface tension because they have lower inter-molecular forces of attraction.

EDIT:- Benzene, Ethanol and Methanol are non-polar molecules & have roughly same surface tension (which differ due to size of particles).