Baking soda breaks up on heating: $2\text{NaHCO}_3 \rightarrow \text{Na}_2\text{CO}_3 + \text{H}_2\text{O} + \text{CO}_2$. What mass of carbon dioxide comes from $16.8\ \text{g}$ of baking soda? Use $\text{NaHCO}_3 = 84$ and $\text{CO}_2 = 44\ \text{g/mol}$.