1.4Li+O2=2Li2O
2.Li2O+H2O=2LiOH
32LiOH+H2SO4=Li2SO4+2H2O
Mr(H2O)=18Mr(h2)=2Mr(O)=16W(H)=2/18=0.11=11%W(O)=16/18=0.89=89%