A portion of potassium oxide, $\text{K}_2\text{O}$, is mixed with $250\,\text{cm}^3$ of distilled water. A $25.0\,\text{cm}^3$ aliquot of the resulting solution is titrated with sulfuric acid of concentration $2.00\,\text{mol dm}^{-3}$. A volume of $15.0\,\text{cm}^3$ of this sulfuric acid is required for complete neutralisation. What mass of potassium oxide had initially been dissolved in $250\,\text{cm}^3$ of distilled water?
- A$2.83\,\text{g}$
- B$28.3\,\text{g}$
- C$47.1\,\text{g}$
- D$56.6\,\text{g}$