An analytical chemist weighs out 0.150g of an unknown monoprotic acid into a 250mL volumetric flask and dilutes to the mark with distilled water. He then titrates this solution with 0.1900MNaOH solution. a) 0.012 M [H₃O⁺], 1.58 × 10⁻⁵ for Ka b) 0.019 M [H₃O⁺], 2.11 × 10⁻⁶ for Ka c) 0.025 M [H₃O⁺], 3.04 × 10⁻⁷ for Ka d) 0.031 M [H₃O⁺], 4.12 × 10⁻⁸ for Ka