The appearance of the pink color was due to the movement of a. phenolphthalein molecules from low concentration to high concentration b. base molecules from high concentration through the membrane to low concentration c. water molecules through the membrane from high concentration to low concentration d. phenolphthalein molecules in the water from high concentration to low concentration

b. base molecules from high concentration through the membrane to low concentration

Note: the complete question is found in the attachment below

Explanation:

The process which enabled the color change in the water and phenology mixture is known as diffusion.

Diffusion is the movement of molecules from regions of higher concentration to regions of lower concentration until equilibrium concentration is attained.

In the setup by the student, the concentration of the base molecules are higher in container than in the test tube. The vaporized molecules of the base therefore, moved through the membrane into the water and phenolphthalein mixture, resulting in the color change to pink in the mixture due to the reaction of the base and the phenolphthalein.

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