选项 | 实验目的 | 实验方案 |
A | 鉴别CO2和N2 | 用燃着的木条,观察火焰是否熄灭 |
B | 鉴别AgNO3与Na2SO4溶液 | 取样,滴加BaCl2溶液,观察是否有白色沉淀 |
C | 鉴别NH4Cl固体和(NH4)2SO4固体 | 取样,加入NaOH固体,研磨,闻气味 |
D | 鉴别白色CuSO4固体和NaCl固体 | 取样,加水溶解,观察颜色 |
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