P2O5
M (P2O5)= 31*2+16*5=62+80=142
w(P)= 62/142*100%=44%
w(O)=80/142*100%=56%
H2SO4
M (H2SO4)= 2*36+16*4=102
w (H)= 2/102*100%=2%
w(S)= 36/102*100%=35%
w(O)=64/102*100%=63%
P2O5
M (P2O5)= 31*2+16*5=62+80=142
w(P)= 62/142*100%=44%
w(O)=80/142*100%=56%
H2SO4
M (H2SO4)= 2*36+16*4=102
w (H)= 2/102*100%=2%
w(S)= 36/102*100%=35%
w(O)=64/102*100%=63%