Water is a universal solvent, which means it can dissolve many substances. However, not all substances are soluble in water. Solubility in water depends on various factors such as the nature of the solute, the temperature and pressure of the solution, etc. Let’s dive deeper into this topic.
Nature of the Solute
The nature of the solute determines whether it is soluble in water. There are two types of solutes – polar and non-polar. Polar solutes are those that have an electrical charge, which means they can dissolve in water. On the other hand, non-polar solutes are those that do not have an electrical charge, which makes them insoluble in water.
Examples of Polar Solutes
Examples of polar solutes include salts, acids, and bases. These solutes are made up of ions, which are electrically charged particles. When these ions come in contact with water, they dissociate and get surrounded by water molecules, which is called hydration. This process allows the polar solutes to dissolve in water.
|Solubility in Water
|Sodium Chloride (NaCl)
|Sodium Hydroxide (NaOH)
|Sulfuric Acid (H2SO4)
Examples of Non-Polar Solutes
Examples of non-polar solutes include oils, fats, and waxes. These solutes are non-polar because they do not have an electrical charge. As a result, they cannot undergo hydration and dissolve in water. Instead, they tend to clump together, which is called aggregation, and do not mix with water.
|Solubility in Water
Temperature and Pressure
The solubility of a solute in water also depends on the temperature and pressure of the solution. In general, increasing the temperature of the solution increases the solubility of polar solutes and decreases the solubility of non-polar solutes. On the other hand, increasing the pressure of the solution increases the solubility of both polar and non-polar solutes.
Solubility of Polar Solutes
When the temperature of a solution increases, the kinetic energy of the water molecules also increases. This allows the water molecules to surround the ions more effectively, increasing the number of hydrated ions in the solution. As a result, the solubility of polar solutes increases with temperature.
Solubility of Non-Polar Solutes
Non-polar solutes do not undergo hydration, so their solubility is not affected by temperature in the same way as polar solutes. In general, increasing the temperature of the solution decreases the solubility of non-polar solutes. This is because the increased kinetic energy of the water molecules can break the weak intermolecular forces between the non-polar solute molecules, causing them to aggregate and form a separate phase.
Total Dissolved Solids (TDS)
Total Dissolved Solids (TDS) is a measurement of the combined content of all inorganic and organic substances contained in a liquid in molecular, ionized, or micro-granular suspended form. The TDS value is affected by the temperature and pressure, as well as the nature of the solutes. High TDS levels can affect the taste of water and can also contribute to the formation of scale in plumbing systems.
Factors Affecting TDS
- The presence of salts, minerals, and metal ions in the water
- Industrial and agricultural pollution
- The weathering of rocks and soil erosion
- The presence of organic compounds such as algae, bacteria, and other microorganisms
Effects of High TDS Levels
High TDS levels can affect the taste of water, making it unappealing to drink. It can also contribute to the formation of scale in plumbing systems, reducing the lifespan of pipes and appliances. In addition, high TDS levels can affect the performance of water treatment processes, making it more difficult to remove pollutants and contaminants from the water.
The Most Common Questions and Answers
- What are some examples of polar solutes that are soluble in water?
- Sodium chloride (NaCl)
- Calcium carbonate (CaCO3)
- Sulfuric acid (H2SO4)
- What are some examples of non-polar solutes that are insoluble in water?
- What is Total Dissolved Solids (TDS)?
- What are the effects of high TDS levels?
Total Dissolved Solids (TDS) is a measurement of the combined content of all inorganic and organic substances contained in a liquid in molecular, ionized, or micro-granular suspended form.
High TDS levels can affect the taste of water, contribute to the formation of scale in plumbing systems, and affect the performance of water treatment processes.
- Environmental Protection Agency. (n.d.). Total Dissolved Solids (TDS) Test. Retrieved from https://www.epa.gov/sites/production/files/2015-08/documents/total-dissolved-solids.pdf
- Masterton, W.L., & Hurley, C.N. (2017). Chemistry: Principles and Reactions (8th ed.). Cengage Learning.
- Russell, J.B., & Lee, J. (2005). Chemistry: The Molecular Nature of Matter and Change (3rd ed.). McGraw-Hill.