溶液中Cl- 的浓度和Ag+ 的浓度均为0.010 mol/L ,问溶液中NH3的初始浓度至少应控制为多少才能防止AgCl沉淀析出。

在100.0 ml 0.15 mol/L K[Ag(CN)2]溶液中加入 50.0 ml 0.10 mol/L KI溶液,是否有AgI沉淀产生?若在上述混合物中再加入50.0 ml 0.20mol/L KCN溶液,是否有AgI沉淀产生?

现有AgBr晶体0.500g,若将其全部溶解,问在1升水中应加入多少克Na2S2O3晶体。

等体积混合0.30 mol/L NH3、0.30 mol/L NaCN和0.030 mol/L AgNO3,计算混合溶液中[Ag(NH3)2]+、[Ag(CN)2]-、NH3、CN- 的平衡浓度。

Lucy and I _____ close friends.

A. is
B. are
C. am

We are close friends, but this doesn’t mean that we never quarrel _____ each other.

A. in
B. at
C. with

Wang Li and I have been close friends _____ more than 10 years.

A. for
B. in
C. on

Where ____ you ____ last Saturday?

A. have; went
B. do; go
C. did; go

Whether you go or not ____ none of my business.

A. is
B. are
C. be

库存现金账应该分别设置库存现金总账和库存现金日记账，并分别核算总账和现金日记账。（ ）

A. 对
B. 错