# How many grams are in .345 moles of Cu?

Approx. $20 \cdot g$
$\text{Mass"="moles"xx"molar mass}$
$=$ $0.345 \cdot \cancel{m o l} \times 63.55 \cdot g \cdot \cancel{m o {l}^{-} 1}$ $=$ ??g