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Sugar easily dissolves when mixed with water just like salt. The molecules of sugar easily break up and they do not form again after the water molecules pull them away from each other. The attraction between sugar molecules and water depends on the charges emitted by each one. The sugar molecules contain hydroxyl groups having little negative charge. The positive charge of oxygen on the other hand found in the water molecules attaches with sugar forming a shell that shields it from other sugar molecules. This shield helps in preventing the sugar from clustering together.
Sugar does not sometimes dissolve completely
Sometimes sugar may not completely dissolve. One reason can be that the solution might not be stirred well; another reason is that the solution is cold before sugar was mixed in it.
Before sugar completely dissolves, the solution should be stirred up of shaken well. The molecules in the container move striking each other and when they collide with water, the sugar breaks up binding with water molecules. After this, the water molecules spread out making place for the sugar molecules.
When the solution is not stirred well, the sugar will stay at the bottom but it will not remain for long like that. The sugar molecules will still dissolve but with a bit longer time.
Heating speeds up the process
The second law of thermodynamics explains that adding heat to a system like a solution increases the movement of molecules in the solution. When sugar and water solution are heated to increase the temperature, the molecule movement also increases. The sugar dissolves faster in this way because heat energy expands the water molecules making place for the sugar.
Other sugars
Besides sucrose, a chemical name for table sugar, there are also other sugars like fructose and glucose and they easily dissolve in water. When exposed to heat, they react positively. The sugars are called water soluble substances.
Salt
Salt also dissolves faster when exposed to heat just like sugar. This can be easily observed when salt is mixed during cooking. On the other hand, gases do not dissolve in water quickly when heated. This is the possible reason why carbonated drinks must be stored in a cold place to make the gas molecules mix with the liquid. If not, the drink will lose its fizz when left in warm place for long.
Salt conducts electricity and sugar does not
Salt breaks up into charged particles called ions when mixed with water. This makes the saline solution to be able to conduct electricity; this is the reason that they are called electrolytes. On the other hand, sugar does not break up into charged particles and this is the reason they are called non-electrolytes.
