Calculate the mass in grams of 0.15 mole of `H_2O`.

Explanation

To calculate the mass in grams of 0.15 moles of \( H_2O \), follow these steps:

### Step 1: Identify the given information
- Moles of \( H_2O \) = 0.15 moles

### Step 2: Determine the molar mass of \( H_2O \)
- The molar mass of water (\( H_2O \)) can be calculated as follows:
- Hydrogen (H) has an atomic mass of approximately 1 g/mol.
- Oxygen (O) has an atomic mass of approximately 16 g/mol.

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

### Step 3: Use the formula to calculate mass
- The formula to calculate mass from moles and molar mass is:
\[ \text{Mass} = \text{Moles} \times \text{Molar Mass} \]

### Step 4: Substitute the values into the formula
- Substitute the values into the formula:
\[ \text{Mass} = 0.15 \text{ moles} \times 18 \text{ g/mol} \]

### Step 5: Perform the calculation
- Calculate the mass:
\[ \text{Mass} = 0.15 \times 18 = 2.7 \text{ grams} \]

### Final Answer
- The mass of 0.15 moles of \( H_2O \) is **2.7 grams**.

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