A.证明一瓶红棕色气体是溴蒸气还是二氧化氮,可用湿润的碘化钾-淀粉试纸检验,观察试纸颜色的变化 |
B.铝热剂溶于足量稀盐酸再滴加KSCN溶液,未出现血红色,铝热剂中一定不含Fe2O3 |
C.测氯水的pH,可用玻璃棒蘸取氯水点在pH试纸上,待其变色后和标准比色卡比较 |
D.检验Cu2+和Fe3+离子,采用径向纸层析法,待离子在滤纸上展开后,用浓氨水熏, 可以检验出Cu2+ |
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