选项 | 实验目的 | 实验操作 |
A | 将硬水软化 | 沉淀、过滤、吸附 |
B | 鉴别NaCl、NaOH、NH4NO3固体 | 加水溶解 |
C | 粗盐中难溶性杂质的去除 | 溶解、加AgNO3溶液沉淀、过滤 |
D | 鉴别CO2和HC1气体 | 将气体通入石蕊溶液中、观察现象 |
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