Question

The solubility of which of the following compounds does not change much with change in temperature (1) \(\mathrm{NaCl}\) (2) \(\mathrm{NaOH}\) (3) \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) (4) \(\mathrm{Na}_{2} \mathrm{SO}_{4}\)

Short answer

NaCl

Step-by-step solution

- Understand Solubility and Temperature Relationship

The solubility of most solid substances in water increases with temperature. However, some compounds have solubility that is relatively temperature-independent.

- Identify Compounds

Consider the four given compounds: \ (1) \(\text{NaCl}\), \ (2) \(\text{NaOH}\), \ (3) \(\text{Na}_2\text{CO}_3\), \ (4) \(\text{Na}_2\text{SO}_4\)

- Compare Solubility Behavior

Solubility of \(\text{NaCl}\) does not change significantly with temperature compared to the others. \(\text{NaOH}\) and \(\text{Na}_2\text{CO}_3\) show considerable increase in solubility with temperature. \(\text{Na}_2\text{SO}_4\) shows different solubility behavior depending on the temperature variations.

- Conclusion

Based on the comparison, \(\text{NaCl}\) is the compound whose solubility is least affected by changes in temperature.

Key concepts

solubility and temperature relationship

The solubility of a compound tells us how well it dissolves in a solvent, usually water. In general, the solubility of most solid substances increases as the temperature increases. This is because higher temperatures provide more kinetic energy to the molecules, which helps break the bonds in the solid.
However, it’s important to note that there are exceptions. Some compounds show very little change in solubility with temperature. This can be due to various factors such as the nature of the intermolecular forces in the substance and the dissolving process itself.
For example, consider substances like NaCl. We’ll see that its solubility doesn’t change much with temperature.

NaCl

Sodium chloride, commonly known as NaCl, is table salt. It is a classic example when discussing solubility and temperature. Unlike many other compounds, the solubility of NaCl in water does not significantly increase with temperature.
This is because the dissolving process for NaCl involves breaking ionic bonds and forming ion-dipole interactions with water molecules. The energy required to break these bonds and the energy released during the interaction with water is relatively balanced, resulting in minimal change in solubility with temperature variations.
Understanding this behavior is crucial for applications where temperature control is difficult, and consistent solubility is needed.

comparative solubility behavior

When comparing the solubility behavior of different compounds, it becomes clear that each has unique properties. Consider the following:

• NaOH: Sodium hydroxide shows a significant increase in solubility with a rise in temperature. This is because the increased kinetic energy at higher temperatures helps break down the solid NaOH more effectively.
• Na₂CO₃: Sodium carbonate also exhibits a marked increase in solubility with temperature. This is due to similar reasons as NaOH.
• Na₂SO₄: Sodium sulfate has a more complex behavior. Its solubility varies noticeably with temperature changes, but it doesn't follow the simple pattern seen in NaOH or Na₂CO₃.

In comparison, NaCl's solubility remains relatively constant across a range of temperatures. This makes it a unique and useful compound in various industrial and laboratory settings where stable solubility is crucial.