Вычислите массовые доли каждого элемента в следующих соединениях а) МgO b) CO2 h) Al2O3 k) KMnO4

MgO

Mr (MgO) = Ar (Mg) + Ar (O) = 24+16=40

w (Mg) = Ar (Mg) / Mr (MgO) = 24/40=0.6=60%

w (O) = Ar (O) / Mr (MgO) = 16/40=0.4=40%

Ответ: w (Mg) = 60%, w (O) = 40%

Al2O3

Mr (Al2O3) = Ar (Al) * 2+Ar (O) * 3=27*2+16*3=102

w (Al) = Ar (Al) * 2/Mr (Al2O3) = 54/102=0.529=53%

w (O) = Ar (O) / Mr (Al2O3) = 48/102=0.470=47%

Ответ:w (Al) = 53%. w (O) = 47%

KMnO4

Mr (KMnO4) = Ar (К) + Ar (Mn) + Ar (O) * 4=39+55+16*4=158

w (K) = Ar (K) / Mr (KMnO4) = 39/158=0.246=25%

w (Mn) = Ar (Mn) / Mr (KMnO4) = 55/158=0.348=35%

w (O) = Ar (O) * 4/Mr (KMnO4) = 64/158=0.40=40%

Ответ:w (K) = 25%, w (Mn) = 35%, w (O) = 40%