选项 | 操作及现象 | 结论 |
A | 向硫酸四氨合铜溶液中加入乙醇,析出深蓝色晶体 | 乙醇的极性比水的弱 |
B | 常温下,向铝片上滴加浓硝酸,没有明显现象 | 铝片与浓硝酸不反应 |
C | 向含淀粉的溶液中滴加硝酸酸化的双氧水,溶液变蓝色 | 氧化性: |
D | 向苯、甲苯中分别滴加酸性溶液,前者不褪色,后者褪色 | 甲基活化了苯环 |
A.A | B.B | C.C | D.D |
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