Question

Given: Ammonia NH3

Determine the mass of hydrogen in a 2.50-gram sample of ammonia.
Show work using dimensional analysis:

Answer 1

`\large \boxed{\text{0.44 g}}}`

Explanation:

1. Calculate the molar mass of ammonia

1 N = 1 × 14.01 g = 14.01 g

3 H = 3 × 1.008 g = 3.024

TOTAL = 17.03 g

2. Calculate the mass of hydrogen

So, there are 3.024 g of H in 17.03 g of NH₃.

The conversion factor is either

`\frac{\text{3.024 g H}}{\text{17.03 g NH}_(3)} \text{ or } \frac{\text{17.03 g NH}_(3)}{\text{3.024 g H}}`

We want to find grams of H, so we choose the first one.

`\text{Mass of H} = \text{2.5 g NH}_(3) * \frac{\text{3.024 g H}}{\text{17.03 g NH}_(3)} = \textbf{0.44 g H}\\\\\text{The mass of H is $\large \boxed{\textbf{0.44 g}}$}`