A strong electrolyte is one which .......

Options

A. is completely ionised in the solution
B. dissociates partially in solution
C. is having low electrical conductivity
D. Ionises partially

Explanation

**Step-by-Step Text Solution:**

1. **Definition of Electrolyte**: An electrolyte is a substance that dissociates into ions when dissolved in a solvent, typically water. This dissociation allows the solution to conduct electricity.

2. **Strong Electrolyte Characteristics**: A strong electrolyte is defined as a substance that completely dissociates into its ions in solution. This means that when a strong electrolyte is dissolved in water, it breaks down entirely into its constituent ions.

3. **Example of Dissociation**: For example, if we consider a strong electrolyte like sodium chloride (NaCl), when it is dissolved in water, it dissociates completely into sodium ions (Na⁺) and chloride ions (Cl⁻).

4. **Electrical Conductivity**: Strong electrolytes have high electrical conductivity because the complete dissociation into ions results in a large number of charge carriers (ions) in the solution. The more ions present, the better the solution can conduct electricity.

5. **Comparison with Weak Electrolytes**: In contrast, weak electrolytes only partially dissociate in solution, resulting in fewer ions and lower conductivity.

6. **Examples of Strong Electrolytes**: Common examples of strong electrolytes include strong acids (like hydrochloric acid, HCl), strong bases (like sodium hydroxide, NaOH), and soluble salts (like potassium nitrate, KNO₃).

**Final Answer**: A strong electrolyte is one which completely dissociates into its ions in solution.

---