Question

Найдите массовые доли элементов: Na3CO4, H3PO4

Answer 1

В формуле ошибка, правильно Na2CO3

w=(Ar*a/Mr)*100%

1). Ar(Na) = 23, Ar(C) = 12, Ar(O) = 16, Mr(Na2CO3) = 106

w(Na) = (23*2/106) * 100% = 43.4%

w(C) = (12*1/106) * 100% = 11.3%

w(O) = 100% - (43.4 + 11.3) = 45.3%

2). Ar(H) = 1, Ar(P) = 31, Ar (O) = 16, Mr(H3PO4) = 98

w(H) = (1*3/98) * 100% = 3.1%

w(P) = (31*1/98) * 100% = 31.6%

w(O) = 100% - (3.1 + 31.6) = 65.3%

Answer 2

H3PO4 аналогично, если есть вопросы - пиши