both lauric acid and sucrose are molecular substances, but one is polar and the other is nonpolar. compare the solubility of the two compounds in water and in acetone to determined which is which

Polar molecules are soluble in polar solvents whereas non polar molecules are soluble in non-polar solvents.
Generally all organic molecules are soluble in organic solvents.

Lauric acid is a carboxylic acid with 12 carbon atoms. Long hydrophobic part(carbon chain) present in the molecule doesn't allows it to dissolve in water as it is a polar solvent. Being organic molecule it will get easily dissolved in organic solvents that is acetone . As it is insoluble in water(polar solvent) it is considered as non polar molecule.

In sucrose there are several hydroxyl groups (-OH) and their presence makes the sucrose molecule polar in nature. These hydroxyl groups have high tendency to form hydrogen bonds with water molecules by which sucrose molecule gets easily dissolved in water. Being organic molecule it will also get dissolved in acetone as well.