Particle size vs dissolving rate of sucrose

I’m required to make a lab with this information only (particle size vs dissolving rate of a solid (molecular covalent compound-sucrose)? so far what I’m thinking is using three different kinds of sugar like table sugar, sugar cubes, and one of them grinding it but the issues is how do you find how they dissolving rate?




I have found in Germany sugar crystals that are about 5 mm thick. If you are able to get some, you may drop one of these crystals in a beaker with 50 mL water and an stirring bar. If not take a standard sugar cube. Using a watch, measure how long it takes for the crystal to be dissolved. Now start again with another rotating speed. Now break a new crystal in two or three parts with a hammer. And start again with smaller crystals (to be weighed in advance). Repeat the measurements. Report these values on a graph vs rotating rate, or vs. weight of sugar, or vs. temperature. Now start again with powder, and even with the sugar powder used in bakery which is made of extremely fine grains. This is just ideas. 


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For one, pure water has a certain [refractive index](https://en.wikipedia.org/wiki/Refractive_index), $n\_D = 1.333$ at a temperature of $20\,^\circ{}\mathrm{C}$. For the other, the presence of a solute *alters* this optical property, which is used, for example to estimate the sugar content in grapes (see, for example an earlier answer by mine [here](https://chemistry.stackexchange.com/questions/110392/what-are-some-ways-to-measure-sugar-concentration-of-fruits/110401#110401)).


«Calibrating your tools» would now request that you prepare a number of samples with known concentration of sugar from nothing = pure water to the max = an saturated solution; each charaterized by its refractive index. Note that the relation between the sugar concentration $c$ and the refractive index $n$ recorded *need not* to be a linear one.


With this information in hand, find a large beaker and a stop watch, and repeatedly measure the *time variant* refractive index quicly. The *temperture variant* approach already was determined, e.g. [here](https://www.sciencedirect.com/science/article/pii/S026087741730362X).


In terms of sugar samples with different granularity, maybe you find sieves in a group working about soil chemistry / geology or process chemistry because knowledge of particle size distributions is of importance to model mecahnical properties, transfer of heat and matter across pebbles / grains of catalyst, etc. ([Sieve analysis](https://en.wikipedia.org/wiki/Soil_mechanics#Sieve_analysis) is a keyword.)


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