To change the `P^(H)` of a solution from I to 1.301. Which of the following should be adopted?

Options

A. 1 lit of water is to be added
B. 1 kg of water is to be added
C. The volume of the solution should be doubled by adding water
D. The wt of the solute present in the solution should be doubled

Answer

To solve the problem of changing the pH of a solution from 1 to 1.301, we need to understand the relationship between pH, hydrogen ion concentration, and dilution. Here’s a step-by-step solution:

### Step 1: Understand pH and Hydrogen Ion Concentration
- The pH of a solution is defined as the negative logarithm of the hydrogen ion concentration (\([H^+]\)):
\[ pH = -\log[H^+] \]
- A pH of 1 corresponds to a hydrogen ion concentration of:
\[ [H^+] = 10^{-1} \, \text{M} = 0.1 \, \text{M} \]

### Step 2: Calculate the Target Hydrogen Ion Concentration
- To find the hydrogen ion concentration corresponding to a pH of 1.301:
\[ [H^+] = 10^{-1.301} \approx 0.0495 \, \text{M} \]

### Step 3: Determine the Change in Concentration
- We need to decrease the hydrogen ion concentration from 0.1 M to approximately 0.0495 M. This indicates that the solution must be diluted.

### Step 4: Analyze the Options
- **Option 1**: Add 1 liter of water.
- **Option 2**: Add 1 kg of water.
- **Option 3**: Double the volume of the solution by adding water.
- **Option 4**: Double the weight of the solute present in the solution.

### Step 5: Identify the Correct Option
- To increase the pH (decrease the acidity), we need to dilute the solution.
- **Option 3** (doubling the volume of the solution by adding water) will effectively dilute the concentration of hydrogen ions, thus increasing the pH to the desired level.

### Conclusion
The correct answer is **Option 3**: The volume of the solution should be doubled by adding water.

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