# How many moles are there in 168 grams of C_2H_4?

Approx. $6$ $\text{moles}$.
$\text{Molar quantity"="Mass"/"Molar mass}$
$\text{Moles of ethane } = \frac{168 \cdot \cancel{g}}{28.05 \cdot \cancel{g} \cdot m o {l}^{-} 1}$ $=$ ??*mol.