Final answer:
The time to dissolve sugar in hot water depends on the water's temperature, amount of sugar, and agitation. Sugar dissolves faster in hot water and the process is expedited by stirring. The solubility limit is higher in hot water, but once reached, additional sugar won't dissolve.
Step-by-step explanation:
The time it takes for sugar to dissolve in hot water can vary depending on several variables such as temperature, the amount of sugar, and whether the solution is agitated. When sugar is added to hot water, the heat increases molecular motion, which in turn increases the rate of dissolution. This is why sugar dissolves faster in hot water compared to cold. Agitation of the solution, like stirring, also plays a significant role in the dissolution process. Stirring the solution allows fresh solvent molecules to constantly contact the sugar, helping it to dissolve more rapidly. Without stirring, the process is slower because the water molecules at the surface of the sugar become saturated, making it harder for more sugar to dissolve. The time it would take for sugar to dissolve fully without stirring can be quite lengthy, which is why stirring is often employed to speed up the process.
It is also important to note that the solubility—the maximum amount of sugar that can dissolve in a certain amount of water—increases with temperature. Once the solubility limit is reached, adding more sugar will not increase the concentration regardless of stirring or increased temperature.