# What is the mass of five moles of oxygen gas?

Well in one mole of $\text{dioxygen gas}$ there are $32.00 \cdot g$........
So.........in $5 \cdot m o l$, there are $5.0 \cdot \cancel{m o l} \times 32.00 \cdot g \cdot \cancel{m o {l}^{-} 1} = 160 \cdot g$. Do you agree?
What is the mass of $5.00 \times {10}^{-} 3 m o l$?