A:H2(g)+1/2O2(g)===H2O(g)ΔH =—a1 kJ/mol
B:H2(g)+CuO(s)===Cu+H2O(l)ΔH =-a2 kJ/mol
C:2H2(g)+O2(g)===2H2O(l)ΔH =-a3 kJ/mol
D:H2(g)+1/2O2(g)===H2O(l)ΔH =-a4 kJ/mol
实验序号号
稀硝酸的体积/mL
剩余固体的质量/g
NO的体积/L
①
100
17.2
2.24
②
200
8.00
4.48
③
400
0
V
下列说法正确的是( )
先化简,再求值:( a2−4a2−4a+4 ﹣ 12−a )÷ 2a2−2a ,其中a是方程x2+3x+2=0的根.