A:用SO2水溶液吸收Br2:SO2 + Br2+2H2O =4H+ + SO+2Br-
B:用稀硫酸除去铜绿:4H++Cu2(OH)2CO3===2Cu2++CO2↑+3H2O
C:酸性高锰酸钾和过氧化氢制取少量氧气:4MnO+4H2O2+12H+=4Mn2++7O2↑+10H2O
D:用惰性电极电解硫酸铜溶液:2Cu2++ 2H2O 2Cu +O2↑ +4H+
下列物质长期敞口放置于空气中,质量会减小的是( )
A: don't we go out to play? B: Because it's raining.