You mix a yellow liquid with water, and they seem to distribute evenly, leaving one pastel yellow solution. You then mix a blue liquid with water, and the blue liquid stays as it's own layer on top. Which of these two liquid's molecules experience the stronger electrical forces?

The molecules of the yellow liquid experience the stronger intermolecular electrical forces.

Explanation:

Immiscible liquids with different densities mixed in water will form layers.

The liquid with the highest density will stay at the bottom of the mixture, the liquid with the second highest density will stay right above the liquid with the highest density, and so on, up to the liquid with the lowest density stay on top.

The density of the liquids is related with the intermolecular forces. The intermolecular forces are of electrical nature: the stronger the electrical forces between the molecules of the liquid, the closer the molecules of the same liquid will be, the smaller the space they occupy, and the higher the density of the liquid.

Hence, the stronger the electrical forces betweem the molecules, the higher the density and the lower the liquid layer will stay in the mixture.

Since the blue liquid stays as it's own layer on top, the yellow liquid stays as it's own layer below the blue liquid, meaning that the molecules of the yellow liquid experience the stronger intermolecular electrical forces.