-0.1823=E0 - 0.05916log[F-} -0.2446=Eo - 0.05916log{[F-]25/30 + 5x1.07x10-3/30} 0.0623=0.05916log{([F-]25/30 + 5x1.07x10-3/30)/[F-]} 11.3=([F-]25/30 + 5x1.07x10-3/30)/[F-] [F-]=1.700x10-5 M 100 mL F-摩尔=4x1.700x10-5=6.80x10-5 摩尔==〉129x10-3 克该牙膏试氟离质量数129x10-3/4 =323x10-4=0.032%