Рассчитать массовые доли элементов в молекуле Cu3(PO4)2

Mr(Cu3(PO4)2) = Mr = 3Ar(Cu) + 2Ar(P) + 8Ar(O) = 3 * 64 + 2 * 31 + 8 * 16 = 382

w(Cu) = 3Ar(Cu) / Mr = (3 * 64) / 382 = 0.5026 = 50.26%

w(P) = 2Ar(P) / Mr = (2 * 31) / 382 = 0.1623 = 16.23%

w(O) = 1 - w(Cu) - w(P) = 1 - 0.5026 - 0.1623 = 0.3351 = 33.51%