Calculate the mass in grams of 0.13 mole of `H_2O`.

Options

A. 2.34g
B. 1.34g
C. 3.41g
D. 22.4g

Explanation

To calculate the mass in grams of 0.13 moles of \( H_2O \), follow these steps:

### Step 1: Identify the molar mass of \( H_2O \)
The molar mass of water (\( H_2O \)) can be calculated by adding the atomic masses of its constituent elements:
- Hydrogen (H): Approximately 1 g/mol (there are 2 hydrogen atoms)
- Oxygen (O): Approximately 16 g/mol (there is 1 oxygen atom)

So, the molar mass of \( H_2O \) is:
\[ \text{Molar mass of } H_2O = (2 \times 1 \, \text{g/mol}) + (1 \times 16 \, \text{g/mol}) = 2 + 16 = 18 \, \text{g/mol} \]

### Step 2: Use the formula to calculate mass
The formula to relate moles, mass, and molar mass is:
\[ \text{Moles} = \frac{\text{Mass (g)}}{\text{Molar Mass (g/mol)}} \]
Rearranging this formula to find the mass gives:
\[ \text{Mass (g)} = \text{Moles} \times \text{Molar Mass (g/mol)} \]

### Step 3: Substitute the values
Substituting the given values into the equation:
\[ \text{Mass (g)} = 0.13 \, \text{moles} \times 18 \, \text{g/mol} \]

### Step 4: Calculate the mass
Now, perform the multiplication:
\[ \text{Mass (g)} = 0.13 \times 18 = 2.34 \, \text{g} \]

### Conclusion
The mass of 0.13 moles of \( H_2O \) is **2.34 grams**.

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