Final answer:
Potassium chloride will conduct the most electricity when dissolved in water because it is a strong electrolyte and dissociates completely into ions, which are needed for electrical conductivity.
Step-by-step explanation:
The student is asking which substance, when dissolved in water, will conduct the most electricity. Among the options given, potassium chloride (KCl) will conduct the most electricity when dissolved in water because it is a strong electrolyte. When potassium chloride dissolves in water, it dissociates completely into potassium (K+) and chloride (Cl-) ions, which are the freely mobile, charged species necessary for conducting electricity.
The other substances listed—ethanol, acetic acid, and ammonia—do not produce as many ions in solution. Ethanol is a nonelectrolyte and does not conduct electricity when dissolved in water. Acetic acid is a weak electrolyte, meaning that it only partially dissociates into ions and therefore conducts electricity weakly. Ammonia forms ammonium (NH4+) and hydroxide (OH-) ions to some extent, but not as much as a strong electrolyte like potassium chloride.
Therefore, confirmed by data and diagrams showing electrical conductance in aqueous solutions (such as Figure 7.5.1 and Figure 9.8.1), potassium chloride is the correct answer because of its high conductivity due to the presence of its fully dissociated ions in solution.