Ответ:
дано
Al2(SO4)3
----------------
W(Al)-?
W(S)-?
W(O)-?
M(Al2(SO4)3) = 27*2+32*3+16*4*3 = 342 g/mol
W(Al) = 27 * 2 / 342 * 100% = 15.79%
w(S) = 32 * 3 / 342 * 100% = 28.07%
W(O) = 16*12 / 342 * 100% =56.14%
Объяснение: