Calculate the no. of mole in 25 g of `NHO_3`

Options

A. 693
B. 369
C. 0.396
D. 245

Explanation

To calculate the number of moles in 25 g of \( \text{NH}_3 \), we can follow these steps:

### Step 1: Determine the Molecular Weight (Molar Mass) of \( \text{NH}_3 \)

The molar mass of a compound is calculated by adding the atomic masses of all the atoms in the molecular formula.

- Nitrogen (N) has an atomic mass of approximately 14 g/mol.
- Hydrogen (H) has an atomic mass of approximately 1 g/mol. Since there are three hydrogen atoms in \( \text{NH}_3 \), we multiply the atomic mass of hydrogen by 3.

So, the calculation is:
\[ \text{Molar mass of } \text{NH}_3 = \text{Atomic mass of N} + 3 \times \text{Atomic mass of H} = 14 + (3 \times 1) = 14 + 3 = 17 \text{ g/mol} \]

### Step 2: Use the Formula to Calculate Moles

The number of moles can be calculated using the formula:
\[ \text{Number of moles} = \frac{\text{Given weight}}{\text{Molar mass}} \]

Here, the given weight is 25 g and the molar mass we calculated is 17 g/mol.

So, substituting the values:
\[ \text{Number of moles} = \frac{25 \text{ g}}{17 \text{ g/mol}} \approx 1.47 \text{ moles} \]

### Final Answer

The number of moles in 25 g of \( \text{NH}_3 \) is approximately **1.47 moles**.

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