(1)2H2O2 =2 H2O+ O2 ↑
————68————32
————X ————O.64g
68:x=32:0.64g 解得x=1.36g
H2O2%=1.36g÷5g=27.2%
(2)m(H2O2原有)=500g×30%=150g
m(H2O2现有)=500g×27.2%=136g
m(H2O2已分解)=150g-136g=14g
(1)2H2O2 =2 H2O+ O2 ↑
————68————32
————X ————O.64g
68:x=32:0.64g 解得x=1.36g
H2O2%=1.36g÷5g=27.2%
(2)m(H2O2原有)=500g×30%=150g
m(H2O2现有)=500g×27.2%=136g
m(H2O2已分解)=150g-136g=14g