The molarity of a solution containing 5.0 g of `NaOH` in 200 mL solution is

Options

A. 0.1
B. 0.5
C. `1.0`
D. `2.0`

Explanation

To find the molarity of a solution containing 5.0 g of NaOH in 200 mL of solution, we can follow these steps:

### Step 1: Calculate the number of moles of NaOH
The number of moles can be calculated using the formula:

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

**Given weight of NaOH** = 5.0 g

**Molar mass of NaOH**:
- Sodium (Na) = 23 g/mol
- Oxygen (O) = 16 g/mol
- Hydrogen (H) = 1 g/mol

\[ \text{Molar mass of NaOH} = 23 + 16 + 1 = 40 \text{ g/mol} \]

Now, substituting the values:

\[ \text{Number of moles} = \frac{5.0 \text{ g}}{40 \text{ g/mol}} = 0.125 \text{ moles} \]

### Step 2: Convert the volume of the solution from mL to L
To calculate molarity, we need the volume in liters.

\[ \text{Volume in L} = \frac{200 \text{ mL}}{1000} = 0.200 \text{ L} \]

### Step 3: Calculate the molarity of the solution
Molarity (M) is defined as the number of moles of solute per liter of solution:

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

Substituting the values we calculated:

\[ \text{Molarity (M)} = \frac{0.125 \text{ moles}}{0.200 \text{ L}} = 0.625 \text{ M} \]

### Final Answer
The molarity of the solution is **0.625 M**.

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