Sodium oxide reacts with water to produce sodium hydroxide. \( 20.0 \, \text{g} \) of sodium oxide is dissolved in \( 500 \, \text{mL} \) of water. Neglecting the change in volume, the concentration of the resulting NaOH solution is _______ \( \times 10^{-1} \, \text{M} \). (Nearest integer) [Atomic mass: \( \mathrm{Na} = 23.0 \), \( \mathrm{O} = 16.0 \), \( \mathrm{H} = 1.0 \)]
