A:540
B:300
C:180
D:150
将一定质量的固体NH4I置于密闭容器中,在某温度下发生下列反应:
①NH4I(s)⇌NH3(g)+HI(g)
②2HI(g)⇌H2(g)+I2(g)
5min后达平衡时,c(H2)=0.5mol/L,c(HI)=4mol/L,则下列说法不正确的是( )
下列变化不属于化学变化的是( )
This black bag is very nice, but it"s very____(重的).