Equal volumes of 10% (w/v) of HCl is mixed with 10% (w/v) NaOH solution. The resultant solution be

Options

A. basic
B. neutral
C. acidic
D. can't be predicted

Answer

To solve the problem of mixing equal volumes of 10% (w/v) HCl and 10% (w/v) NaOH solutions, we will follow these steps:

### Step 1: Understand the Concentration
The concentration of the solutions is given as 10% (w/v). This means that there are 10 grams of solute (HCl or NaOH) in 100 mL of solution.

### Step 2: Calculate the Number of Equivalents for HCl
- The molecular weight of HCl is approximately 36.5 g/mol.
- In a 10% (w/v) solution, there are 10 grams of HCl in 100 mL.
- To find the number of equivalents of HCl:

\[ \text{Number of equivalents of HCl} = \frac{\text{mass of HCl}}{\text{molecular weight of HCl}} = \frac{10 \text{ g}}{36.5 \text{ g/mol}} \approx 0.274 \text{ equivalents} \]

### Step 3: Calculate the Number of Equivalents for NaOH
- The molecular weight of NaOH is approximately 40 g/mol.
- In a 10% (w/v) solution, there are 10 grams of NaOH in 100 mL.
- To find the number of equivalents of NaOH:

\[ \text{Number of equivalents of NaOH} = \frac{\text{mass of NaOH}}{\text{molecular weight of NaOH}} = \frac{10 \text{ g}}{40 \text{ g/mol}} = 0.25 \text{ equivalents} \]

### Step 4: Compare the Number of Equivalents
- From the calculations:
- HCl has approximately 0.274 equivalents.
- NaOH has 0.25 equivalents.
- Since HCl has more equivalents than NaOH, it indicates that there is an excess of HCl.

### Step 5: Determine the Nature of the Resultant Solution
- Since there are more equivalents of HCl than NaOH, the resultant solution will be acidic in nature.

### Conclusion
The resultant solution of mixing equal volumes of 10% (w/v) HCl and 10% (w/v) NaOH will be **acidic**.