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
Explanation:
An electrolyte is a substance that produces ions when it is dissolved in water or molten, making the solution capable of conducting electricity. The correct answer is chemical change, because the process of ion formation involves breaking chemical bonds and forming charged particles—ions—which is a hallmark of a chemical change.
Why not physical change?
A physical change affects the form of a substance, but does not alter its chemical composition. For example, melting ice into water or dissolving sugar in water are physical changes, as no new substances are formed. In contrast, when an electrolyte such as sodium chloride (NaCl) dissolves in water, it dissociates into Na⁺ and Cl⁻ ions. This process involves breaking ionic bonds, leading to the formation of new species (ions) in solution. This is a chemical change.
Chemical change and ion formation
Chemical changes involve transformations that result in the formation of new substances. In the case of strong electrolytes (e.g., NaCl, HCl, KOH), the compounds completely dissociate into ions:
- NaCl (s) → Na⁺ (aq) + Cl⁻ (aq)
- HCl (aq) → H⁺ (aq) + Cl⁻ (aq)
This chemical dissociation is necessary for conduction of electricity. Weak electrolytes (like acetic acid, CH₃COOH) also undergo partial chemical dissociation into ions, which still qualifies as a chemical change.
Why not spontaneous change?
A spontaneous change refers to a process that occurs without outside intervention, such as rusting. While some ionization processes may be spontaneous, spontaneity refers to the tendency of a reaction, not the type of change (physical or chemical). Hence, it’s not the best descriptor here.
Why not “depends on the substance”?
Although different substances may behave differently (strong vs. weak electrolytes), all electrolytes produce ions via chemical changes in water or molten state. Therefore, it does not depend on the substance in terms of the type of change involved—it is always a chemical change.