An electrolyte will yield ions by undergoing a:
Select the correct answer below:
physical change
chemical change
spontaneous change
depends on the substance
The Correct Answer and Explanation is:
Correct Answer: Chemical change
An electrolyte is a substance that, when dissolved in water or molten, yields ions, allowing the solution to conduct electricity. This ion production involves a chemical change rather than a mere physical change. Let’s break down why this is the correct choice.
Explanation:
A chemical change is a transformation that alters the chemical composition of a substance, typically involving the breaking and forming of chemical bonds. For an electrolyte, this change is necessary because the original compound (usually a salt, acid, or base) dissociates into its constituent ions when it dissolves in water. For example:
- NaCl (table salt) dissociates in water: $$
\text{NaCl (s)} \rightarrow \text{Na}^+ (aq) + \text{Cl}^- (aq)
$$
This dissociation represents a chemical change because it involves breaking the ionic bonds in the solid crystal and forming new interactions with water molecules (hydration of ions).
In contrast, a physical change would involve changes in state (e.g., melting or boiling) or appearance without changing the molecular composition. Simply melting a solid or dissolving a sugar cube (non-electrolyte) in water may be a physical change, but no ions are formed, and the substance doesn’t conduct electricity.
The option “spontaneous change” refers to whether a process occurs on its own without external input, which is unrelated to the definition of an electrolyte.
The option “depends on the substance” might sound reasonable, but it is vague. While it is true that some substances dissociate more completely than others (strong vs. weak electrolytes), any substance acting as an electrolyte must undergo a chemical change to yield ions.
Conclusion:
Thus, the formation of ions from an electrolyte involves a chemical change because it changes the substance’s chemical structure and allows the solution to conduct electricity. This change is essential to the fundamental behavior of electrolytes in both biological systems and industrial applications.