论文部分内容阅读
《1999年全国初中学生化学素质和实验能力竞赛》复赛试题中有这样一道题 :测得某溶液中含 Cu2 + ,K+ ,SO42 -,Cl-四种离子 ,且阳离子的个数比为 Cu2 +∶ K+ =3∶ 4,则 SO42 -与 Cl-的个数比可能是 ( )。A .3∶ 2 B.1∶ 3 C.1∶ 8 D.2∶ 5此类题前几年在刊物上曾有评?
In the 1999 National Junior High School Students’ Chemical Quality and Experimental Ability Contest, there was a question in the semi-finals: the solution contains Cu2 +, K+, SO42 -, and Cl- ions, and the number of cations is Cu2 +. : K+ = 3: 4, then the ratio of SO42- to Cl- may be (). A .3 : 2 B.1 : 3 C.1 : 8 D.2 : 5 There has been a review of such questions in previous publications for several years.