Answer:
Ethanol
Explanation :
The molecular structure of ethanol C2H5OH it is seen that there is a hydrogen atom attached to an oxygen atom, hence hydrogen bonding. This makes it has a greater surface tension than dimethyl ether.
Dimethy ether however has dipole moment in its structure. Dipole moments are said to be existent in a molecule when the charges are separated. This makes dimethyl ether have a lower surface tension. In the molecular tructure of dimethyl ether CH3OCH3) the oxygen atom is a negative atom in between two positive methyl group.