Sugar dissolving in water is both physical and chemical change…Let me explain.
In high school, the correct answer would be “Physical Change” since no bonds between atoms are made or broken, the students cannot consider it to be chemical.]
However, in reality, things are more complicated than that, and non-covalent bonds between water and sugar can also be considered a chemical change. What’s even more surprising is that now, many sugars can open and close rings when in water solutions.
Hence why we said, sugar dilution in water is both physical and chemical phases.
What Change Is Dissolving Sugar in Water?
Sugar dissolving in water is both a physical change and a chemical change.
When sugar dissolves in water, a small amount is produced. This heat is known as a “heat of solution”.
This heat stems from the chemical reaction between the sugar 9solute) and the water (solvent).
The fact that the process is reversible (e.g. boiling off the water) doesn’t change the fact that the chemistry of sugar molecules changed – they indeed were attracted to and bonded with, the constituents of the water (H+, OH-, and/or H2O itself).
Personally, I believe where a bit of the problem might lie is the arbitrariness of middle-school science where artificial either/or descriptions can be presented. Is a hydrated sugar molecule the same chemically as an anhydrous sugar molecule?
A typical person would say “It’s still sugar”. However, as a chemist, I would argue and prove that “they are different molecules, with different spectra”.
Now, which one would you believe? I thought so, too. Arguing which of these is the “right” point of view is pretty meaningless.
Is Dissolving Sugar in Hot Water A Chemical Change?
Yes. Sugar dissolving in water is a both chemical and physical change.
You can pretty much boil the water to get the sugar back. Why? Because all it’s doing is that the water molecules surround the sugar molecules, making it seem like it dissolves but is a classic physical change example. Now, if it changes color or temperature, smells weird (though the smell might hurt you), and gives off a gas, generally, it is considered a chemical change since it makes something new.
Explain Why Dissolving Sugar In Water Is Not A Chemical Change
In Highschool, Dissolving sugar in water is considered a physical change because sugar molecules are dispersed. Still, the individual molecules remain unchanged or do not go through any process of chemical change.
ALSO SEE: Is Toasting Bread A Chemical Change or Physical Change?
Is Dissolving Sugar in Water Reversible or Irreversible?
Yes, dissolving sugar in water is a reversible change because water and sugar can be extracted back from the solution by crystallization followed by evaporation.