Read the passage carefully and answer the questions.
Electrochemistry is the study involving two types of processes. One type involves the production of electricity from the energy released during a spontaneous chemical reaction. Galvanic cells like Daniel cells are used to produce electricity from the redox reaction. Nernst equation of a galvanic cell gives the relation between the standard cell potential and the concentration of the species involved in the redox reaction. The second type of study involves the cells in which electrical energy is used to bring about the chemical reactions in a non-spontaneous process. The conductance of electrolytic solution depends on many factors including the nature of the electrolyte and the dimensions of the electrolytic cell.
When \( KCl \) is dissolved in water, the Potassium ion is;
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Hydrated
An ionic solid such as KCl dissolves in water because its ions are attracted by the polar water molecules. Each ion becomes surrounded by a sheath of water molecules (ion–dipole attraction); the energy released in this process, the hydration enthalpy, helps to break up the crystal lattice. When the solvent is water, this solvation is called hydration.
\( \displaystyle \ce{KCl(s)} \xrightarrow{\ce{H2O}} \ce{K+(aq) + Cl^-(aq)} \)
The potassium ion is surrounded by water molecules with their negative oxygen ends turned towards it. So in water \( \ce{K+} \) is present as a hydrated ion, \( \ce{K+(aq)} \).
Why the other options are incorrect
Option (1) Oxidized — Incorrect. Oxidation means loss of electrons. Potassium is already +1 in KCl and stays +1 in solution; dissolution transfers no electrons.
Option (2) Reduced — Incorrect. Reduction would turn \( \ce{K+} \) into K metal, which needs electrolysis of the molten salt; it does not happen on dissolving.
Option (4) Hydrolyzed — Incorrect. Hydrolysis is a reaction of an ion with water that changes the pH. \( \ce{K+} \) is the cation of the strong base KOH, so it does not react with water; a KCl solution stays neutral.