2Na+2H2O=2NaOH+H2↑ Na2O+H2O=2NaOH 2Na2O2 +2H2O=4NaOH+O2 ↑ 2H2 +O2 =2H2O
反應(yīng)消耗氣體為224mL-56mL=168mL
其中V(H2 )=112mL V(O2 )=56mL
1)若剩余氣體56mL為H2
則V(H2 )=112mL+56mL=168mL 氫氣的物質(zhì)的量為0.168÷22.4=7.5×10-3mol
V(O2 )=56mL 氧氣的物質(zhì)的量為0.056÷22.4=2.5×10-3mol
n(Na)=2n(H2 )=1.5×10-2mol
n(Na2O2)=2n(O2)=5×10-3mol
∴ m(Na)=1.5×10-2mol×23g/mol=0.345g
m(Na2O2 )= 5×10-3mol×78g/mol=0.390g
m(Na2O)=1.1g-0.345g-0.390g=0.365g
2)若剩余氣體56mL為O2
則V(H2 )=112mL 氫氣的物質(zhì)的量為5×10-3mol
V(O2 )=56mL+56mL=112mL 氧氣的物質(zhì)的量為5×10-3mol
n(Na)=2n(H2 )=1×10-2mol
n(Na2O2 )=2n(O2 )=1×10-2mol
∴ m(Na)=1×10-2mol×23g/mol=0.23g
m(Na2O2 )= 1×10-2mol×78g/mol=0.78g
m(Na2O)=1.1g-0.23g-0.78g=0.09g
答：1)若剩余氣體56mL為H2,Na、Na2O、Na2O2的質(zhì)量分別為0.345g、0.365g、0.39g；
2)若剩余氣體56mL為O2,Na、Na2O、Na2O2的質(zhì)量分別為0.23g、0.09g、0.78g.