What is the molarity of 2.00 g of NaOH dissolved in a total solution volume of 250 mL?

Explanation

To find the molarity of a solution, we can follow these steps:

### Step 1: Identify the given values
- Mass of NaOH = 2.00 g
- Volume of solution = 250 mL

### Step 2: Convert the volume from mL to L
Molarity is defined as moles of solute per liter of solution. Therefore, we need to convert the volume from milliliters to liters.

\[ \text{Volume in L} = \frac{250 \text{ mL}}{1000} = 0.250 \text{ L} \]

### Step 3: Calculate the number of moles of NaOH
To find the number of moles, we use the formula:

\[ \text{Number of moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}} \]

The molar mass of NaOH (Sodium Hydroxide) is approximately 40 g/mol. Thus, we can calculate the number of moles:

\[ \text{Number of moles} = \frac{2.00 \text{ g}}{40 \text{ g/mol}} = 0.050 \text{ moles} \]

### Step 4: Calculate the molarity
Now that we have the number of moles and the volume in liters, we can calculate the molarity using the formula:

\[ \text{Molarity (M)} = \frac{\text{number of moles}}{\text{volume in L}} \]

Substituting the values we have:

\[ \text{Molarity} = \frac{0.050 \text{ moles}}{0.250 \text{ L}} = 0.20 \text{ M} \]

### Final Answer
The molarity of the NaOH solution is **0.20 M**.

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