300 gm aq. NaOH solution contains 100 gm NaOH. Find (w/v)%

Answer

To find the weight/volume percent (w/v%) of the NaOH solution, we can follow these steps:

### Step 1: Identify the mass of the solute
The mass of the solute (NaOH) is given as 100 grams.

### Step 2: Identify the total mass of the solution
The total mass of the aqueous NaOH solution is given as 300 grams.

### Step 3: Convert the mass of the solution to volume
Since the density of water is approximately 1 g/mL, we can assume that the density of the solution is also close to 1 g/mL for dilute solutions. Therefore, the volume of the solution in milliliters is equal to its mass in grams. Thus, 300 grams of solution corresponds to 300 mL of solution.

### Step 4: Calculate the weight/volume percent (w/v%)
The formula for weight/volume percent is given by:

\[ \text{w/v\%} = \left( \frac{\text{mass of solute (g)}}{\text{volume of solution (mL)}} \right) \times 100 \]

Substituting the values we have:

\[ \text{w/v\%} = \left( \frac{100 \text{ g}}{300 \text{ mL}} \right) \times 100 \]

### Step 5: Simplify the calculation
Calculating the fraction:

\[ \frac{100}{300} = \frac{1}{3} \]

Now, multiplying by 100 to convert to percentage:

\[ \text{w/v\%} = \frac{1}{3} \times 100 = 33.33\% \]

### Final Answer
The weight/volume percent (w/v%) of the NaOH solution is **33.33%**.

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