Which of the following ion is expected to have highest value of molar conductivity at infinity at infinite dilution is the aqueous solution ?

Options

A. `Na^(+)`
B. `K^(+)`
C. `Ca^(2+)`
D. `H^(+)`

Answer

To determine which ion has the highest molar conductivity at infinite dilution in an aqueous solution, we can follow these steps:

### Step 1: Understand Molar Conductivity
Molar conductivity (\( \Lambda_m \)) is a measure of the ability of an ion to conduct electricity in solution. It is defined as the conductivity of the solution divided by the molar concentration of the electrolyte. At infinite dilution, each ion behaves independently, and interactions between ions are minimized.

**Hint:** Molar conductivity increases with the mobility of ions in solution.

### Step 2: Identify the Ions
Consider the ions typically compared for molar conductivity, such as \( H^+ \), \( Na^+ \), \( K^+ \), \( Cl^- \), and \( OH^- \).

**Hint:** Focus on common ions in aqueous solutions, especially those that are known to have high mobilities.

### Step 3: Evaluate Ion Mobility
The mobility of an ion in solution is influenced by its size and charge. Smaller ions or those with higher charges generally have higher mobilities. Among the common ions, \( H^+ \) (proton) is unique due to its ability to "hop" through hydrogen bonds in water.

**Hint:** Consider the unique properties of the \( H^+ \) ion compared to other ions.

### Step 4: Understand Proton Hopping
Proton hopping refers to the rapid movement of protons through the hydrogen-bonded network of water molecules. This phenomenon allows \( H^+ \) to move much faster than other ions, leading to a significantly higher molar conductivity.

**Hint:** Remember that the structure of water plays a crucial role in the behavior of protons.

### Step 5: Conclusion
Based on the above analysis, we conclude that \( H^+ \) has the highest molar conductivity at infinite dilution in an aqueous solution due to its unique mobility facilitated by proton hopping.

**Final Answer:** The ion expected to have the highest value of molar conductivity at infinite dilution in an aqueous solution is \( H^+ \).