If atomic mass of nitrogen is 14u and atomic mass of hydrogen is 1u, what is the molar mass of ammonia?

Options

A. 14u
B. 15u
C. 17u
D. 18u

Explanation

To find the molar mass of ammonia (NH₃), we can follow these steps:

### Step 1: Write the Formula for Ammonia
The chemical formula for ammonia is NH₃.

### Step 2: Identify the Atomic Masses
From the question, we know:
- Atomic mass of nitrogen (N) = 14 u
- Atomic mass of hydrogen (H) = 1 u

### Step 3: Count the Atoms in the Formula
In the formula NH₃:
- There is 1 nitrogen atom.
- There are 3 hydrogen atoms.

### Step 4: Calculate the Contribution of Each Element
- Contribution of nitrogen:
\[ 1 \text{ atom of N} \times 14 \text{ u} = 14 \text{ u} \]
- Contribution of hydrogen:
\[ 3 \text{ atoms of H} \times 1 \text{ u} = 3 \text{ u} \]

### Step 5: Add the Contributions Together
Now, we add the contributions from nitrogen and hydrogen:
\[ \text{Total molar mass of NH₃} = 14 \text{ u} + 3 \text{ u} = 17 \text{ u} \]

### Conclusion
The molar mass of ammonia (NH₃) is 17 u.

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