The formula of quinine is C20H24N2O2 and the respective atomic weights are C= 12.0096 , H = 1.008, N=14.0067 and O=15.9994 so C x 20 = 24.192 and H x24= 24.192 and N x 2 = 28.0134 and O x 2 = 31.998 for an approximate total of 324.4 grams/mole for the molecular weight of quinine.