Question

Distinguish between an electrolyte and a nonelectrolyte.

Short answer

An electrolyte is a substance that, when dissolved in water, results in a solution capable of conducting electricity due to the disassociation of the substance into positive and negative ions. A nonelectrolyte, however, does not disassociate into ions when dissolved in water, hence it does not produce a solution that can conduct electricity.

Step-by-step solution

Define Electrolyte

An electrolyte is a substance that, when dissolved in water, results in a solution that can conduct electricity. This is because an electrolyte disassociates into positive and negative ions in the solution. These ions are capable of moving, thereby conducting electricity.

Define Nonelectrolyte

On the other hand, a nonelectrolyte is a substance that does not disassociate into ions when it is dissolved in water. Consequently, a solution of a nonelectrolyte is incapable of conducting electricity because there are no free ions to move and conduct an electric current.

Comparison

The primary difference between an electrolyte and a nonelectrolyte is that an electrolyte produces a solution that can conduct electricity, while a nonelectrolyte does not.

Key concepts

Chemical Conductivity

When we talk about chemical conductivity, we refer to a material's ability to allow the flow of electric charge. In the context of solutions, this charge flow occurs through ions—atoms or molecules that have gained or lost electrons and thus carry a charge.

Materials that produce ion-rich solutions when dissolved in water are good conductors because these ions act as charge carriers. To understand why some solutions conduct electricity while others don't, we need to explore the nature of the substances being dissolved. Electrolytes, such as salts, acids, and bases, break down into cations (positively charged ions) and anions (negatively charged ions) in water. These ions facilitate the movement of charge, essentially 'carrying' electricity through the solution.

On the contrary, nonelectrolytes do not produce these charged particles when dissolved; substances like sugar or ethanol, even when in a solution, do not change the solution’s capacity to conduct electricity.

Ion Disassociation

The process of ion disassociation is essential to understanding the behavior of electrolytes. When you dissolve an electrolytic substance in water, it undergoes a process called disassociation or ionization. During this process, the compound separates into individual ions. Each ion is surrounded by water molecules in a specific manner, with water's polar nature facilitating the ionization process.

For example, when table salt (sodium chloride, NaCl) is dissolved in water, it separates into Na+ and Cl- ions. This separation is crucial for the solution’s ability to conduct electricity. The extent of disassociation varies according to the electrolyte's strength: strong electrolytes disassociate completely, while weak electrolytes only partially disassociate, creating fewer ions and thus lower conductivity.

Electric Current in Solutions

Understanding electric current in solutions is a key to mastering the applied aspects of chemistry and physics. An electric current is the flow of charged particles. In metallic conductors, these are electrons. In ionic solutions—such as those containing an electrolyte—the current flows by the movement of ions.

The ions move towards electrodes with a charge opposite to their own during electrolysis or when placed in an electric field: cations move towards the cathode (negative electrode), and anions travel towards the anode (positive electrode). This movement is what we observe as an 'electric current' in a solution. It's crucial to note that pure water hardly conducts electricity. However, impurities in water, such as electrolytes, enhance its conductivity dramatically, which is why tap and sea water are much better conductors than distilled water.