Calculate the mass in grams of 0.17 mole of `H_2O`.

Options

A. 3.06g
B. 4.78g
C. 0.45g
D. 0.36g

Explanation

To calculate the mass in grams of 0.17 moles of \( H_2O \), follow these steps:

### Step 1: Determine the Molar Mass of \( H_2O \)

1. **Identify the elements in \( H_2O \)**: The compound consists of hydrogen (H) and oxygen (O).
2. **Find the atomic masses**:
- Atomic mass of hydrogen (H) = 1 g/mol
- Atomic mass of oxygen (O) = 16 g/mol
3. **Calculate the molar mass**:
- There are 2 hydrogen atoms in \( H_2O \), so the contribution from hydrogen is:
\[ 2 \times 1 \, \text{g/mol} = 2 \, \text{g/mol} \]
- The contribution from oxygen is:
\[ 1 \times 16 \, \text{g/mol} = 16 \, \text{g/mol} \]
- Therefore, the total molar mass of \( H_2O \) is:
\[ 2 \, \text{g/mol} + 16 \, \text{g/mol} = 18 \, \text{g/mol} \]

### Step 2: Use the Molar Mass to Calculate the Mass

1. **Use the formula**:
\[ \text{mass} = \text{moles} \times \text{molar mass} \]
2. **Substitute the values**:
- Moles of \( H_2O \) = 0.17 moles
- Molar mass of \( H_2O \) = 18 g/mol
\[ \text{mass} = 0.17 \, \text{moles} \times 18 \, \text{g/mol} \]
3. **Calculate the mass**:
\[ \text{mass} = 3.06 \, \text{grams} \]

### Final Answer
The mass of 0.17 moles of \( H_2O \) is **3.06 grams**.

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