Ответ:

Объяснение:

Mr(HClO4) =Ar(H) + Ar(Cl) + Ar(O) * 4 = 1 + 35,5 + 16 * 4 = 100,5

w(H) = Ar(H)/Mr(HClO4) * 100% = 1/100,5 * 100% = 1%

w(Cl) = Ar(Cl)/Mr(HClO4) * 100% = 35,5/100,5 * 100% = 35,32%

w(O) = Ar(O) * n/Mr(HClO4) * 100% = 16 * 4/100,5 * 100% = 63,68%