分析化学各章练习题及答案

1、在一定温度下离子强度增大,HAc的浓度常数Ka将 ········· ( ) A.减小 B.增大 C.不变

2、H3PO4的pKa1-pKa3分别为,,,其中pKb3是 ············· ( ) 、H3PO4的pKa1-pKa3分别为,,,其中pH=的H3PO4溶液,其主要形式是 ··························· ( )

?2?3?A.H3PO4~H2PO4 B. H3PO4~PO4

cC.HPO42?

D. H2PO4

-

4、H3AsO4的pKa1~pKa3分别为,,。pH=的H3AsO4的主要平衡关系式是 ···· ( )

??2?A.H3AsO4?H2AsO4 B. H2AsO4?HAsO4

C. HAsO4?AsO4 D. H3AsO4?H2AsO43?2?3??

5、H3AsO4的pKa1~pKa3分别,,,pH=时[H3AsO4]/[AsO4]的比值是 ····· ( )

D. 10

6、二乙三胺五乙酸(H5L)的pKa1~pKa5分别为,,,,。其溶液中的Na2H3L组分浓度最大的

pH值是 ···························· ( ) D.

7、L的NaH2PO4(pH1)和NH4H2PO4(pH2)两种溶液pH关系是 ········ ( )

=pH2 >pH2 <pH2

8、H2A的pKa1=,pKa2=。溶液中当[H2A]=[A] 时的pH值是 ······· ( ) 、H2C2O4的pKa1=, pKa2=,H2S的pKa1=,pKa2=,Na2S和Na2C2O4溶液碱性由强到弱的顺序是 ·············· ( )

10、浓度为cmol/L的Ag[NH3]2溶液的物料平衡式是 ·········· ( )

A.[Ag]=[NH3]=c [NH3]=[Ag]=c C.[Ag]+Ag[NH3]2 +[Ag(NH3)]=c D.[Ag]+Ag[NH3]2+[Ag[NH3]]=c

11、浓度为cmol/L的Na2CO3的溶液的物料平衡是 ············ ( )

?[Na]+[CO3]=c B.[H2CO3]+[HCO3]+CO3=c

2-

+++

+

2-

???+

+

2?C.[Na]=2c [Na]=[CO3]=c

12、NaCN溶液的质子条件是 ····················· ( )

++

2?A.[H]=[OH]-[HCN] B. [OH]=[H]+[HCN] C. [H]=[OH]+[HCN] D. [OH]=[H]-[HCN]

13、浓度为cmol/L的Na2S溶液的质子条件是 ············· ( )

A.[OH]=[H]+[HS]+2[H2S] B.[H]=[OH]-[S]+[H2S]+c C. [OH]=[H]-[HS]-2[H2S] D.[H]=[OH]+[S]-[H2S]-c

14、浓度为cmol/L的NaOH溶液的质子条件是 ············· ( )

+

+

2-

+

2-

+

+

+--+

A.[OH-

]=[H+

]+[Na+

] B.[OH]=[H+

]-c C.[OH-

]=[H+

]+c D.[H+

]=[OH-

]-[Na+

]

15、浓度为c1mol/L的HCN和c2mol/L的NaOH的混合溶液的质子条件是 ·· ( A.[H+

]=[OH-

]+c-

1-c2 B.[OH]=[OH]+c1-[CN]-c2 C.[H+

]=[OH]+c+

1-[HCN]-C2 D.[H]=[OH]+[CN]-c2

16、浓度为cmol/L(NH4)2CO3溶液质子条件是 ············· (A.[H+

]=[OH-

]-[NH3]+[HCO?3]+2[H2CO3]

B.[H+

]=[OH-

]+[NH3]-[HCO?3]-2[H2CO3]

C.[H+

]=[OH-

]-[NH3]-[HCO?3]+2[H2CO3]

D.[NH3]=[HCO?3]

17、浓度c1mol/LHAc-c2mol/L NaAc溶液的质子条件是 ········· (A.[H+

]=[OH-

]+[Ac-

]-[Na+

] B. [H+

]=[OH-

]+[Ac-

]+[Na+

] C. [H-

]+c-

2=[OH]+[Ac-

] D. [H+

]+[Ac-

]=[OH-

]+[Na+

]

18、L NH3~L NH4Cl溶液的质子条件是 ················· (A.[H+

]+[Cl-

]=[OH-

]+[NH?+?--

4] B.[H]+[NH4]=[CH]+[Cl] C.[H+

]=[OH-

]-+[NH+

3] D.[H]=[OH]+-[NH3]

19、用LHCl 滴定LNH3水至计量点的质子条件是 ············ (A.[H+

]=[OH-

]+-[NH+

?3] B.[H]=[OH]-+[NH4] C.[H+

]=[OH-

]+[NH+

?3] D.[H] =[OH]+-[NH4]

20、浓度为L 硼砂水溶液的质子条件是 ················ (A.[H+

]=[H2BO?-[OH] B.[H+

]=[OH-

]+[H?+

3]2BO3]-[Na]

C.[H+

]=[OH-

]+[H+

2BO?]-[H3BO3] D.[H]=[OH]-+[H2BO?33]

21、浓度为cmol/L的Na2C2O4中Na+

的物料平衡是 ············ () )

A.[Na]=c B.[Na]=2c C.[Na]=D.[Na]=2([H2C2O4]+[HC2O4] +[C2O4] )

+++

1c 22?22、浓度为L的NaHSO4(Pka2=)溶液的pH是 ············· ( ) 、浓度为L的NH2OH·HCl (pKb=)溶液的pH是( ) 、浓度为L的NH2OH·HCl(pKb=)溶液的pH是 · ( ) 、L Na3PO4(pKa1=,pKa2=,pKa3=)溶液pH值为 ································· ( ) 、L (NH4)2CO3溶液(NH3的pKb=,pKa1=,pKa2=)pH值是

······························· ( ) 、L(NH4)2S(pKa1=,pKa2=,NH3PKb=)溶液pH值是

······························· ( ) 、L Na2HPO4(pKa1~pKa3分别为,,溶液的pH值是

······························· ( ) 、浓度为L氨基乙酸(pKa1=, pKa2=)溶液的pH值

是( )

、(NH3+NaOH)混合组分的质子条件是( )

A.[OH]=[H]+[NH4]+[Nc] B.[OH]=[H]+[NH4]

C.[OH]=[H]+[Na] D.[H]=[OH]-[NH4]-[Na]

31、浓度为cmol/L的H2SO4和HCOOH混合液的质子条件是 ········ ( )

A.[H]=[OH]+[HSO4]+[SO4+[HCOO] B.[H]=[OH]+C+[SO4]+[HCOO] C.[H]=[OH]+[HSO4]+2[SO4]+[HCOO] D.[H]=[OH]+[HSO4]+2[SO4]

32、用NaOH滴定H3PO4(pKa1~ pKa3分别为,,)至第二计量点,pH值为 ·· ( ) 、含LHAc (Ka=×10

-5

+

+

+

+

+

+

+

+

?+-+

??+

?2?-

2?-

?2?-

?2?)-L NaAc溶液的pH值

································· ( ) 、100ml LHCl 溶液pH由增到时,需加固体NaAc的克数

(忽略体积变化)是 ······················ ( )

、六次甲基四胺(pKb=)配成缓冲溶液的pH缓冲范围是 ································· ( ) ~10 ~6 ~8 ~5

36、欲配制pH=5的缓冲溶液,下列物质可用的是 ············ ( )

(pKa=) B.六次甲基四胺(pKb=) 水(pKb=) (pKa=

37、强酸滴定弱碱应选用的指示剂是 ················· ( )

A.酚酞 B.百里酚酞 C.甲基红 D.百里酚蓝

38、浓度均为LHCl滴定NaOH溶液的突跃范围是pH=~。当浓度改为L时,其滴定突跃范

围是 ····························· ( ) 、下面L的酸不能用NaOH作直接滴定分析 ··· ( )

(pKa=) (pKa= (pKb=) (pKa=12)

40、下列L多元酸(碱)或混合酸(碱)中,能分步(分别)测定的是 ·· ( )

(pKa2=) (pKa1=, pKa2= (pKa1=, pKa2=, pKa3= (pKa1=8, pKa=15) -H3BO3(pKb= -NH4Cl(pKb= -HAc(pKa=

41、用L的NaOH滴定L,pKa=的弱酸,其pH突跃范围是-。用同浓度的NaOH滴定pKa=

的弱酸时,其突跃范围将是 ··················· ( ) 、NaOH滴定H3PO4(pKa1~ pKa3分别为,,至产物为Na2HPO4,应

选用的指示剂是 ························ ( ) A.甲基橙 B.甲基红 C.酚酞 D.百里酚酞

43、有NaOH磷酸盐混合碱,以酚酞为指示剂,用HCl滴定耗去。若滴到甲基橙变色,则

需HCl 。此混合物的组成是 ··················· ( )

44、某生以甲基橙为指示剂用HCl标准液标定含CO3的NaOH溶液,然后用此NaOH测定

试样HAc的含量,则HAc含量将会 ················ ( ) A.偏高 B.偏低 C.无影响

45、下面混合液能出现两个滴定突跃的是 ··············· ( )

-HAc(pKa= -HF(pKa=

-H3PO4(pKa1=, pKa2=, pKa3= -H2C2O2(pKa1=, pKa2=

46、Pb3O4处理成Pb(NO3)2溶液,通H2S至饱和,过滤,滤液用NaOH标液滴定,则Pb3O4

与NaOH的物质的量的比是 ···················· ( ) :3 :1 :6 :1

47、铵盐在催化剂存在下氧化为NO,再氧化为NO2,溶于水得NHO3,用NaOH滴定时,NH4?2?和NaOH的物质的量的比是 ···················· ( ) :1 :3 :2 :3

48、能使H3BO3,HAc, HCl, H2SO4,HNO3,HClO4显示相同强酸度的溶剂是 · ( )

A.丙酮 B.纯水 C.液氨 D.甲基异丁酮 49、 L的H3PO4溶液与 L的Na3PO4溶液混合。稀至100ml。计算pH值和缓冲容量β。取

上述溶液,问需加入多少 ml LNaOH溶液,才能使溶液的pH=。

50、用L NaOH滴定L HCl-L HAc混合溶液中的HCl,问计量点为pH为多少?以甲基橙

为指示剂,滴定的终点误差为多少?

51、浓度均为L的氨基磺酸及其钠盐缓冲溶液的pH为多少?已知pKa=。

52、需加入多少毫升L NaOH到毫升L H3PO4中,才能得到pH=的溶液,已知H3PO4的pKa1=,

pKa2=, pKa3=。

53、配制pH=的弱碱BOH(pKb=)及其盐BCL的200毫升缓冲溶液向其中加入60毫升L HCl

后,pH=,求cBOH和cBCl。

54、已知CCl3COOH的pKa=,今称取其试样克(M=),加入克NaOH配制1000毫升溶液。

问:(1)有人说此溶液pH=,对否?实际pH为多少?(2)欲配制pH=该溶液,需加入强酸多少?

55、甲基橙的理论变色点pH=,加入NaCl使浓度达L,这时甲基橙的理论变色点又为什

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