Провести все возможные расчеты по формуле K2SO4
1) Mr(K2SO4) = 39*2 + 32 + 16*4 =174 2) 78:32:64 = 39:16:32 3) W(K) = Ar(K) * n / Mr(K2SO4) *100% = 39*2 / 174 *100% =45% W(S) = Ar(S) *n / Mr(K2SO4) *100% = 32 *1 / 174 *100% = 18% W(O) = Ar(O) * n / Mr(K2SO4) *100% = 16*4 / 174 *100% = 37%