— Solvent: the liquid in which a solute dissolves
— Solute: the substance that dissolves in the solvent
— Solution: the mixture formed when a solute is dissolved in a solvent
— Saturated solution: the solution when the maximum amount of solute is dissolved in a solvent
- Saltwater is a solution of salt and water.
- Salt is the solute, and water is the solvent.
- If you keep adding salt to water at a constant temperature, you will notice that salt will not dissolve in water anymore and remain as a solid after you add a certain amount of salt. The saltwater that contains the maximum amount of dissolved salt is called saturated solution.
- Solubility is the ability of a solute to dissolve in a solvent
- Solubility measures the maximum amount of solute that can be dissolved in a solvent at a given temperature
- Solubility is expressed in g of solute per 100 g of solvent
- For solids, solubility increases as temperature increases.
- More amount of salt can be dissolved in hot water than in cold water.
- For gases, solubility decreases as temperature increases.
- Sodas are basically a solution of carbon dioxide dissolved in water.
- When the soda is kept at room temperature, there is less fizziness in the soda because solubility has decreased and carbon dioxide has left the soda.
👇 This graph shows the solubility curve of many different solutes. 👇
Examples of information you should be able to get from interpreting this graph:
- The solubility for solid salts, such as NaNO3, KNO3 and NH4Cl, increases as temperature increases.
- The solubility for gases, such as NH3, SO2 and HCl, decreases as temperature increases.
- What is the solubility of NH4Cl at 70°C?
- The solubility of NH4Cl is 60 g of solute / 100 g water at 70 °C.
- At 70°C, how many grams of NH4Cl would I need to prepare a saturated solution if I had 300 g of water?
- 60 x (300 / 100) = 180 g
- If I dissolved 20 g of KCl into 50 g of water at 75 °C, would the solution be saturated?
- The solubility of KCl at 75 °C is approximately 50 g of KCl / 100 g water.
- The maximum amount of KCl that can be dissolved in 50 g of water at 75 °C is 50 x (50 / 100) = 25 g.
- Therefore, the solution is not saturated.