Chemistry · Solution · Solubility / Principles and Exploration
Solubility and saturation — principles and investigation
Whether a solid placed in water dissolves entirely depends not only on the amount of solute, but also on the temperature and mass of the water. Use the solubility curve of a hypothetical substance to compare the amount dissolved and the solid remaining. Saturation means that you have reached the limit of how much more can be dissolved, and does not necessarily mean that there are any solids remaining.
How does it work?
The dissolved amount is the smaller of the added amount and the maximum dissolved amount. Saturation is when the limit of solubility has been reached and no solids necessarily remain.
Maximum dissolution amount = S(T) × mass of water / 100
Try this investigation
- Set the temperature, water mass, and solute mass and execute. Tables and curves are virtual data, not actual materials.
- Run and record 20 g and 50 g of virtual A solute in 100 g of water and 20 °C, respectively.
- Record separately whether you increase the temperature, increase only the water, or change only the substance. Even if you increase the water, the per unit value of solubility S remains the same.
Interpreting your results
What happens if you add more solute to a saturated solution at the same temperature?
If the temperature and mass of water are the same, the melting limit is the same. Solutes that exceed the limit remain as solids.
Assumptions and limitations
This is an educational table of virtual substances A and B. This is not actual reagent data. Assuming 0~100 °C, 1 atm, the unit is g/100 g of water, and linear interpolation is performed between sections. Equilibrium is reached immediately and the water does not evaporate. Melting speed, supersaturation, heat of dissolution, and solution volume are not calculated.