Question

The aqueous solution of non-electrolytes contains (a) atoms (b) ions (c) electrons (d) molecules

Short answer

Answer: (d) molecules.

Step-by-step solution

Understand Non-Electrolytes

A non-electrolyte is a substance that, when dissolved in water, does not conduct electricity. This is because non-electrolytes do not dissociate into ions when in solution. They remain as intact molecules.

Understand Aqueous Solution

An aqueous solution is a liquid mixture where a solute (the given substance) is dissolved in water. The water acts as the solvent, which can dissolve a variety of substances to create the solution.

Determine the Components of Aqueous Solution of Non-Electrolytes

Since non-electrolytes remain as intact molecules when dissolved in water, they don't form ions, atoms, or electrons in the solution. So, the correct answer is that an aqueous solution of non-electrolytes contains (d) molecules.

Key concepts

Aqueous Solution

When we talk about an aqueous solution, we're referring to any mixture where water (H₂O) serves as the solvent. The solvent is the substance that dissolves the solute—the material being dissolved. In an aqueous solution, the solute could be a solid, liquid, or gas that integrates with the water molecules.

For example, when salt (NaCl) is mixed with water, it dissolves into its respective ions, sodium (Na⁺) and chloride (Cl^-). However, with non-electrolytes, the situation is different. These substances dissolve in water without breaking into ions. They disperse throughout the solvent as whole molecules. Hence, solutions containing non-electrolytes, like sugar in water, still consist of intact sugar molecules, even after dissolution. This concept is integral to understanding the behavior of various substances when they interact with water, impacting their biological, chemical, and physical properties.

Electrical Conductivity in Solutions

• Electrical conductivity in solutions is a measure of a solution's ability to conduct electricity.
• Conductivity depends on the presence of ions—charged particles that are formed when a substance dissociates in water.
• Electrolytes, substances that ionize in water and conduct electrical current, come in various forms like salts, acids, and bases.

Electrical conductivity in solutions comes down to the movement of these ions. When a voltage is applied across a solution containing ions, they move toward the electrodes, allowing current to flow.

In contrast, solutions of non-electrolytes lack free ions and thus are poor conductors of electricity. These solutions may conduct minute amounts of electricity due to the presence of a few ions or molecules that can carry a charge, but generally, their conductivity is negligible compared to that of electrolyte solutions.

Molecular Dissociation

Molecular dissociation is a process where a compound separates into smaller components, typically ions, when dissolved in a solvent, like water. The extent of dissociation determines whether a substance is a strong, weak, or non-electrolyte.

Strong electrolytes dissociate completely, such as table salt (NaCl) disintegrating entirely into sodium and chloride ions. Weak electrolytes partially dissociate, leading to a mixture of intact molecules and ions in solution. Examples include acetic acid (CH₃COOH) that partially ionizes in water.

Non-electrolytes, on the other hand, do not dissociate significantly into ions. When sugar dissolves, it does so as whole molecules that spread out through the water but remain chemically unchanged. This distinction is pivotal for understanding the electrical properties of solutions and their chemical reactivity.