\textbf{213-} In 25 mL of a 34 percent by mass ammonia solution with a density of $0.98\ \mathrm{g.mL^{-1}}$, how many moles of ammonia are present and what is the molarity of this solution? (Read the options from right to left.) $(\mathrm{H = 1,\ N = 14 : g.mol^{-1}})$
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(1) $15/7 \circ /49$ \qquad (2) $19/6 \circ /49$ \qquad (3) $15/7 \circ /52$ \qquad (4) $19/6 \circ /52$
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