【单选题】下列滴定中,不能准确滴定的是( )
A.
0.10mol/LHCl 滴定 0.10mol/LNH 3 · H 2 O ( K b =1.75 × 10 -5 )
B.
0.10mol/LNaOH 滴定 0.10mol/LNH 4 Cl
C.
0.10mol/LHCl 滴定 0.10mol/LNaCN ( K a =4.9 × 10 -10 )
D.
0.10mol/LNaOH 滴定 0.10mol/LHCOOH ( K a =1.7 × 10 -4 )
【单选题】下列滴定中,不能准确滴定的是()
A.
0.10mol/LHCl滴定0.10mol/LNH3•H2O(KB=1.75×10-5)
B.
0.10mol/LNAOH滴定0.10mol/LNH4Cl
C.
0.10mol/LHCl滴定0.10mol/LNACN(KA=4.9×10-10)
D.
0.10mol/LNAOH滴定0.10mol/LHCOOH(KA=1.7×10-4)
【判断题】艾滋病全称为获得性免疫综合症(AIDS),会导致免疫力低下,从而十分容易感染其他疾病。( )
【单选题】下列滴定中,不能准确滴定的是( )
A.
0.10mol/LHCl 滴定 0.10mol/LNH3·H2O ( Kb=1.75×10 )
B.
0.10mol/LNaOH 滴定 0.10mol/LNH4Cl
C.
0.10mol/LHCl 滴定 0.10mol/LNaCN ( Ka=4.9×10 )
D.
0.10mol/LNaOH 滴定 0.10mol/LHCOOH ( Ka=1.7×10 )
【单选题】Vanish (v.) means ______ —The magician made the rabbit vanish by slipping it under a secret door. —You gave a stranger $500 in cash to paint your house? How do you know he won’t vanish with the money?
【单选题】下列酸碱中,不能被准确滴定的物质是
A.
NH2OH. HC1[ Kb(NH2OH) = 9.1×10-9 ]
B.
NH4Cl[Kb(NH3) = 1.8×10-5]
C.
(CH2)6N4H+[Kb((CH2)6N4)=1.4×10-9]
【单选题】_____ carelessly, the boy made mistakes here and there. .
【单选题】According to Haley, there is a difference between “being a writer” and writing and the latter means
B.
spending hours at the typewriter writing
C.
expecting the fame and wealth of a writer
D.
mistaking “writing” for wealth and fame
【单选题】根据24节气判断以下有关上饶的描述正确的是 ( )