Welding If 5.50 mol of calcium carbide $\left(\mathrm{CaC}_{2}\right)$ reacts
with an excess of water, how many moles of acetylene
$\left(\mathrm{C}_{2} \mathrm{H}_{2}\right),$ a gas used in welding, will be produced?
\begin{equation}
\mathrm{CaC}_{2}(\mathrm{s})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \rightarrow \mathrm{Ca}(\mathrm{OH})_{2}(\mathrm{aq})+\mathrm{C}_{2} \mathrm{H}_{2}(\mathrm{g})
\end{equation}