1 A
Fe(OH)3
w(O)=(48/107)×100%=44.85%
2 A
Cu3(PO4)2
w(Cu)=(192/382)×100%=50.26%
w(P)=(62/382)×100%=16.23%
w(O)=(128/382)×100%=33.51%
3 Г
Al2O3
w(Al)=(54/102)×100%=53%
w(O)=(48/102)×100%=47%
4 В
5 1-Г, 2-В, 3-Д, 4-1
HCl
w(H)=(1/36.5)×100%=2.74%
NH3
w(H)=(3/17)×100%=17.76%
PH3
w(H)=(3/34)×100%=8.82%
H2O
w(H)=(2/18)×100%=11.11%