When 0.050 mol of propionic acid, C2H5CO2H, is dissolved in 300 ml of water, the equilibrium concentration of H3O+ ions is measured to be 1.37 x 10-3 M. What is Ka for this acid?When 0.050 mol of propionic acid, C2H5CO2H, is dissolved in 300 ml of water, the equilibrium concentration of H3O+ ions is measured to be 1.37 x 10-3 M. What is Ka for this acid?