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 :
The correct answer is: chemical change
Explanation:
An electrolyte is a substance that dissociates into ions when dissolved in water (or another solvent) and thus conducts electricity. This dissociation involves the breaking of chemical bonds or the formation of ions through a chemical process, not just a physical change.
Why not a physical change?
- A physical change involves changes in the state or appearance of a substance without altering its chemical composition. Examples include melting, boiling, dissolving sugar in water, or crushing a solid.
- When an electrolyte dissolves in water, if it were only a physical change, the substance would remain chemically the same in solution (like sugar dissolving). But electrolytes actually ionize, meaning the original molecules or ionic compounds break into charged particles (ions). This alters the chemical form of the substance in solution.
Why a chemical change?
- The process of an electrolyte dissolving often involves ionization or dissociation. For example, when sodium chloride (NaCl) dissolves in water, it dissociates into Na⁺ and Cl⁻ ions.
- This process involves the breaking of ionic bonds between sodium and chloride ions in the solid lattice and the formation of new interactions (hydration) between these ions and water molecules.
- The original compound Ceases to exist as intact molecules or formula units; instead, you have free ions, which is a chemical transformation.
- This ion formation is essential for the electrolyte’s ability to conduct electricity in solution.
What about “spontaneous change”?
- Spontaneous change refers to whether a process occurs naturally without added energy. The dissolution of electrolytes can be spontaneous or not depending on the specific compound and conditions.
- However, spontaneity is about thermodynamics and does not directly address whether the change is physical or chemical.
Does it depend on the substance?
- The nature of the change depends on the substance, but for electrolytes, the key defining feature is the chemical ionization process.
- Some substances dissolve physically (non-electrolytes), and some ionize chemically (electrolytes).
- For instance, sugar dissolves physically; NaCl dissolves chemically as ions form.
Summary
Electrolytes yield ions by undergoing a chemical change because ionization involves breaking and forming chemical bonds, changing the substance’s chemical identity. This is fundamentally different from a physical change, which does not alter the substance’s molecular or ionic structure.