A.2H2+O2=2H2O ΔH=142.9kJ·mol-1 |
B.2H2(g)+O2(g)=2H2O(l) ΔH=-142.9kJ·mol-1 |
C.2H2(g)+O2(g)=2H2O(l) ΔH=-571.6kJ·mol-1 |
D.2H2(g)+O2(g)=2H2O(l) ΔH=+571.6kJ·mol-1 |

同类型试题

y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2


y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2

