Ответ: 1) m(ZnCl2) = nxM = 2×136 = 272 гM(ZnCl2) = 65 + 2×35,5 = 65 + 71 = 136 г/моль2) P2O5, M(P2O5) = 2×31 + 5×16 = 62 + 80 = 142 г/мольW(O) = [5A(O)/M(P2O5)]x100% = [5×16/142]x100% = [80/142]x100% = 56,33 %