Mr

CaO=1*(40+17)=57

O2=2*17=34

CaSO3=1*40+1*32+3*17=123

MgSO4=1*24+1*32+4*17=124

Cu(OH)2=1*65+2*17+2+1=101

Ca3(PO4)2=3*40+2*31+8*17=318

Al(ClO4)3=1*27+3*35+12*17=336

W

1)W(CaO)

Ca=40/57*100%=70%

O=17/57*100%=30%

2)W(O2)=32*17/34*100*=100%

3)W(CaSO4)

Ca=40/123*100%=33%

S=32/123*100%=26%

O3=3*17/123*100%=41%

4)W(MgSO4)

Mg=24/124*100%=19%

S=32/124*100%=26%

O4=4*17/124*100%=55%

5)W(Cu(OH)2)

Cu=65/101*100%=65%

O2=2*17/101*100%=33%

H2=2*1/101*100%=2%

6)W(Ca3(PO4)2)

Ca3=3*40/318*100%=38%

P2=2*31/318*100%=19%

O8=8*17/318*100%=43%

7)W(Al(ClO4)3)

Al=27/336*100%=8%

Cl3=3*35/336*100%=31%

O12=12*17/336*100%=61%