No, corn starch is not soluble in water at room temperature.
While corn starch readily disperses in water, forming a suspension, it doesn't truly dissolve. The starch granules remain intact, although they absorb some water and swell slightly. This is why a mixture of corn starch and water appears cloudy or milky.
To achieve a solution-like state with corn starch, it needs to be heated. When heated in water, corn starch undergoes a process called gelatinization. During gelatinization:
- Water molecules penetrate the starch granules.
- The granules swell significantly and lose their crystalline structure.
- Amylose, one of the two main components of starch (the other being amylopectin), leaches out into the surrounding water.
- The mixture thickens, forming a viscous paste or gel.
Even after gelatinization, it's technically not a true solution in the strictest chemical sense, but rather a colloidal dispersion or a gel. The large starch molecules are dispersed throughout the water, but they are not individually dissolved as table salt (NaCl) would be.
Therefore, corn starch is insoluble in cold water but forms a gel or paste when heated in water due to gelatinization.
