\textbf{220.} If the density of a sample of 6 molar sulfuric acid solution is $1.5\ \text{g.mL}^{-1}$, what is its approximate molality?
$(H = 1,\ O = 16,\ S = 32\ :\ \text{g.mol}^{-1})$
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(1) $6/58$ \quad (2) $6/8$ \quad (3) $5/25$ \quad (4) $5/46$
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