Question

What is the actual mass of one molecule of $NH_3$?

• A. 17 g
• B. 17 amu
• C. $2.82 \times 10^{-23}$ g
• D. $1.02 \times 10^{-23}$ g

Answer 1

Answer: (C)

Molecular mass of $NH_3 = 17$ amu
$1 \,u = 1.66 \times 10^{-24}g$
The actual mass of $NH_3 = 17 \times 1.66 \times 10^{-24}$
$= 2.82 \times 10^{-23}\, g$