【判断题】H2C2O4的第一步、第二步离解常数分别为Ka1=5.6×10-2,Ka2=5.1×10-5,因此不能分步滴定。
【单选题】—Do you know when ____? I miss him very much. —Don't worry. I will tell you as soon as ____. [ ]
A.
will he come; he comes
B.
he will come; he comes
C.
he comes; he will come
D.
he will come; he will come
【判断题】H2C2O4的第一步、第二步离解常数分别为Ka1=5.6×10-2,Ka2=5.1×10-5,因此不能分步滴定。
【单选题】听力原文:M: I met Leila's brother at the dinner party yesterday. Do you know him? W: Of course I know. He is the most talkative man I've ever met, but Leila is a very pleasant person to be with. Q: What c...
A.
He is unpleasant to be with.
B.
He is an introverted person.
C.
He is very enthusiastic.
【单选题】秘书起草一份文件,起草文件是一种( )。
【单选题】用c(NaOH)=0.1000mol/L的NaOH标准滴定溶液滴定c(NaOH)=0.1000mol/L的H 2 C 2 O 4 溶液时,下列说法正确的是()。已知H 2 C 2 O 4 的两级离解常数分别为:K a1 =5.9×10 -2 ,K a2 =6.4×10 -5 。
A.
有一个滴定突跃,可滴定第一、二级电离的H + 总和,但第一、二级电离不可分步滴定
D.
有一个滴定突跃,第一级电离的H + 可被滴定,第二级电离的H+不能被滴定
【单选题】伤口愈合中抗拉力强度的大小主要决定于( )
【单选题】—Why do you call him Mr.Knowledgeable? — Because he knows almost everything we want to know.
【判断题】民营化就是政府通过增加介入与干预但不减弱监督的职责或者通过管理权与经营权的分离来达到鼓励竞争、打破垄断的局面,最终使其经济效益得以提高的过程。
【判断题】Zhè hé niúnǎi guòqī le, hē bu dé.这 盒 牛奶 过期 了, 喝 不 得。