\textbf{214-} To prepare 14.2 liters of chlorine gas from the reaction of manganese dioxide with hydrochloric acid, how many grams of 75\% pure manganese dioxide are needed? (The density of chlorine gas at experimental conditions is $1.25\ \mathrm{g.L^{-1}}$.)
$$(\mathrm{O = 16,\ Cl = 35.5\ ,\ Mn = 55 : g.mol^{-1}})$$
\begin{center}
(1) 27 \qquad (2) 28.5 \qquad (3) 29 \qquad (4) 30.8
\end{center}