Does adding more density to water, such as oil, affect the rate of evaporation of the water?
Adding just about anything to water will affect its rate of evaporation… this includes oil. However, the evaporation rate is due to the intermolecular interactions of the water molecules, not density. (and adding most oils will decrease the density of the resulting oil-water mixture… not increase.) In a nutshell: the water molecules are attracted to each other and hydrogen bonds form between them. evaporation occurs when the bonds are disrupted and individual molecules can break free of the solution. therefore, to increase the evaporation rate, you would need to add something that will disrupt the hydrogen bonds. For example, a good way to do this is adding an alcohol to the water and mixing really well so that its a somewhat homogenous mixture. Then this water-alcohol mixture will evaporate faster than plain water of the same volume.
