Water’s molar mass is 18. 01 g/mol. The molar mass of glycerol is 92. 09 g/mol. At 25°C, glycerol is more viscous than water. Which substance has the stronger intermolecular attraction? glycerol because it has a larger molar mass glycerol because it is more viscous and has a larger molar mass water because it has a lower molar mass water because it is less viscous and has a lower molar mass.