选项 | 实验目的 | 实验方案 |
A | 除去N2中混有的少量O2 | 将混合气体通过灼热的木炭 |
B | 除去KCl中的少量CuCl2 | 先加足量水溶解,再加过量KOH溶液,过滤,蒸发 |
C | 鉴别氮肥尿素[CO(NH2)2]和(NH4)2SO4 | 分别取样,与熟石灰混合研磨,闻气味 |
D | 将硬水转化为软水 | 加入明矾,搅拌、过滤 |
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