# How many molecules of CO_2 are there in 55 grams of CO_2?

There are over $\text{Avogadro's Number}$ carbon dioxide molecules in a 55 g mass.
By definition there are $6.022 \times {10}^{23}$ carbon dioxide molecules in a $44.0 \cdot g$ mass. How do I know this? Well because we use the given number to specify molar mass, the which equates the macro world of grams and kilograms with the micro world of atoms and molecules.
$\text{Number of carbon dioxide molecules } = \frac{55.0 \cdot g}{44.0 \cdot g \cdot m o {l}^{-} 1} \times {N}_{A}$, where ${N}_{A}$ is a number with units $m o {l}^{-} 1$.