Water's molar mass is 18.01 g/mol. The molar mass of methanol is 32.01 g/mol. At room temperature, water is 64% more viscous than methanol. Which substance has the stronger intermolecular attraction?

Thus we can conclude that water has stronger intermolecular forces compared to methanol.

Explanation:

Viscosity of a solution depends directly on the strength of intermolecular forces.

Since water has a higher viscosity than methanol, means that water should have stronger intermolecular forces than methanol.

The molecules of water are more strongly bonded through hydrogen bonds and the dipole moments created by the strong electronegative oxygen and the hydrogen.

Methanol (CH3OH)) also has hydrogen bonds but these are slightly weaker than the hydrogen bonds in water

Thus we can conclude that water has stronger intermolecular forces compared to methanol.