选项 | 实验目的 | 实验方案 |
A | 鉴别涤纶纤维和羊毛纤维 | 分别灼烧,闻气味 |
B | 鉴别KCl固体和NH4Cl固体 | 分别加熟石灰研磨,闻气味 |
C | 检验NaOH溶液是否完全变质 | 取样,滴加石灰水,再滴加酚酞溶液 |
D | 除去CO2中的水蒸气 | 将混合气体通过盛有浓硫酸的洗气装置 |
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