Amongst the following , the form of water with the lowest ionic conductance at 298 K

Options

A. distilled water
B. saline water used for intravenous injection
C. water from a well
D. sea water

Answer

To determine which form of water has the lowest ionic conductance at 298 K, we need to analyze the ionic composition of each type of water given in the options.

### Step-by-Step Solution:

1. **Understanding Ionic Conductance**:
- Ionic conductance refers to the ability of a solution to conduct electricity, which is dependent on the presence of ions in the solution. The more ions present, the higher the conductance.

2. **Analyzing Each Option**:
- **Option A: Distilled Water**:
- Distilled water is purified water that has been boiled and condensed back into liquid. It contains very few ions, primarily just H⁺ and OH⁻ ions from the dissociation of water. Thus, it has the lowest ionic conductance.

- **Option B: Saline Water**:
- Saline water contains a significant amount of dissolved salts, primarily sodium chloride (NaCl), which dissociates into Na⁺ and Cl⁻ ions. This results in high ionic conductance.

- **Option C: Water from a Well**:
- Well water is often considered hard water, which contains dissolved minerals such as calcium (Ca²⁺) and magnesium (Mg²⁺) ions. These ions contribute to a higher ionic conductance than distilled water.

- **Option D: Seawater**:
- Seawater contains a large number of dissolved salts, including NaCl, MgCl₂, and others, leading to a very high concentration of ions. Therefore, it has the highest ionic conductance among the options.

3. **Conclusion**:
- After analyzing all the options, it is clear that distilled water, with its minimal ion content, has the lowest ionic conductance at 298 K.

### Final Answer:
- The form of water with the lowest ionic conductance at 298 K is **distilled water**.