Which term refers to a solution that contains ions and will transmit ions?

• A. Electrolyte
• B. Titrant
• C. Half cell
• D. Primary standard

Answer: (A)

The concept here is that a substance in solution can carry electrical charge only if it forms free ions. An electrolyte is a solution that contains these ions, allowing the movement of charge and thus conduction of electricity. When salts like table salt (sodium chloride) dissolve, they dissociate into positively and negatively charged ions (Na+ and Cl−), which enables current to flow through the solution. Some electrolytes dissociate completely (strong electrolytes), others only partly (weak electrolytes), but both produce ions and conduct to some degree. In contrast, non-electrolytes such as sugar or ethanol do not form ions in solution and therefore do not conduct electricity well. Other terms mentioned relate to different concepts: a titrant is used in titration, a half cell is part of an electrochemical cell, and a primary standard is a highly pure substance used to calibrate measurements. Because the defining feature described is the presence of free ions that enable ion transport, the correct term is electrolyte.