Question

Вычислите массовую долю ( в процентах) химического элемента в веществах : CaCl2 , Na3PO4 , Few(OH)3

Answer 1

CaCl2

W(Ca) = Ar(Ca) * n / Mr(CaCl2) *100% = 40 * 1 / 110 *100% = 36,36%

W(Cl) = Ar(Cl) * n / Mr(CaCl2)  * 100% = 35 * 2 / 110 *100% =63,63%

Na3PO4

W(Na) = Ar(Na) * n / Mr(Na3PO4 *100% = 23 * 3 / 164 *100% = 42%

W(P) = Ar(P) * n / Mr(Na3PO4) *100% = 31 * 1 / 164 *100% = 18,9%

W(O) = Ar(O) * n / Mr(Na3PO4) * 100% = 16 * 4 / 164 *100% = 39%

Fe(OH)3

W(Fe) = Ar(Fe) * n / Mr(Fe(OH)3) *100% = 56 * 1 / 107 * 100% = 52,33%

W(O) = Ar(O) * n / Mr(Fe(OH)3 *100% = 16 * 3 / 107 *100% = 44,86%

W(H) = Ar(H) * n / Mr(Fe(OH)3) *100% = 1*3 / 107 *100% = 2,8%