Question

What types of substances are nonelectrolytes? How do they behave when dissolved in water?

Short answer

Nonelectrolytes are substances that do not ionize when dissolved in water, meaning they cannot conduct electricity. Examples include sugar and alcohol. When dissolved in water, they do not dissociate into ions, hence the solution remains non-conductive.

Step-by-step solution

Define Nonelectrolytes

Nonelectrolytes are substances that do not ionize when dissolved in water and therefore cannot conduct electricity. These are generally compounds that do not form ions when they dissolve in water. Examples include alcohol, sugar, and many other organic compounds.

Explain Behaviour of Nonelectrolytes in Water

When nonelectrolytes are dissolved in water, they do not dissociate into ions. As a result, the solution remains non-conductive. That's because the ability to conduct electricity is tied to the presence of ions, which can move and therefore 'carry' electrical charge. In the case of nonelectrolytes, these ions aren't present, meaning no charge can be carried.

Key concepts

Ionization

Ionization is the process by which molecules split into ions in a solution. For a substance to conduct electricity when dissolved in water, it must undergo ionization. This means the molecules separate into positively and negatively charged ions.

Nonelectrolytes do not undergo this process when mixed in water. Their molecular structures remain intact, preventing them from forming ions.

Because ions are the charge carriers in conductive solutions, the absence of ionization in nonelectrolytes means a lack of these carriers. Consequently, nonelectrolytes can't help water conduct electricity.

• Ionic compounds, when dissolved, produce a solution that conducts electricity due to the presence of ions.
• Nonelectrolytes, such as sugar or alcohol, maintain their molecular form, leading to non-conductive solutions.

Electrical Conductivity

Electrical conductivity in solutions relies on the presence of free moving ions. Conductivity occurs as these ions move when an electric field is applied. The movement of charged particles carries electric charge through the solution.

Nonelectrolytes, however, don't produce free ions when dissolved. This absence translates to zero electrical conductivity in their solutions. In contrast, electrolytes dissolve and dissociate into ions, enabling electric charge flow.

• Water containing electrolytes is conductive due to mobile ions.
• Nonelectrolytic solutions lack mobile charge carriers, and therefore, don't conduct electricity.

Organic Compounds

Many nonelectrolytes are organic compounds, which are typically composed of carbon atoms bonded to hydrogen, oxygen, and other elements. These compounds often do not ionize due to their stable covalent bonds, which tend to remain intact in a water solution.

Examples of organic nonelectrolytes include common sugars and alcohols. They dissolve in water without splitting into ions, allowing the molecular structure to stay as is. This behavior is a reflection of their chemical stability and the non-polar characteristics of many such compounds.

• Organic nonelectrolytes like glucose dissolve but don't conduct electricity.
• The molecular integrity in water leads to non-conductive behavior.