You have a beaker containing exactly 200 mL of pure water. You have a second beaker containing exactly 200 mL of pure alcohol.
They can mix, but they are chemically different.
You take one teaspoonful of water and drop it in the beaker containing alcohol. You now take one teaspoonful of the mixture and return it to the beaker of water.
Now, is there more alcohol in the water, or more water in the alcohol?