搜题请搜索小程序“爱下问搜题”
问题 填空题

一般较强酸可制取较弱酸，这是复分解反应的规律之一．已知在常温下测得浓度均为0.1mol/L的下列6种溶液的pH：

溶质CH3COONaNaHCO3Na2CO3NaClONaCNC6H5ONa
pH8.18.811.610.311.111.3
（1）①请根据上述信息判断下列反应不能发生的是______（填编号）．

A．CH3COOH+NaCN═CH3COONa+HCN

B．CO2+H2O+2NaClO═Na2CO3+2HClO

C．2HCN+Na2CO3-→2NaCN+CO2+H2O

D．Na2CO3+C6H5OH-→NaHCO3+C6H5ONa

E．CO2+H2O+C6H5ONa-→NaHCO3+C6H5OH

②已知HA、H2B是两种弱酸，存在以下关系：H2B（少量）+2A-=B2-+2HA，则A-、B2-、HB-三种阴离子结合H+的难易顺序为______．

（2）一些复分解反应的发生还遵循其他规律．下列变化都属于复分解反应：

①将石灰乳与纯碱溶液混合可制得苛性钠溶液　②向饱和碳酸氢铵溶液中加入饱和食盐水可获得小苏打固体  ③蒸发KCl和NaNO3的混合溶液，首先析出NaCl晶体．根据上述反应，总结出复分解反应发生的另一规律为______．

（3）常温下某电解质溶解在水中后，溶液中的c（H+）=10-9mol．L-1，则该电解质可能是______（填序号）．

A． CuSO4     B． HCl   C． Na2S     D．NaOH   E．K2SO4

（4）常温下，将pH=3的盐酸a L分别与下 * * 种溶液混合，结果溶液均呈中性．

①浓度为1.0×l0-3mol．L-1的氨水b L；

②c（OH -）=1.0×10-3mol．L-l的氨水c L；

③c（OH-）=1.0×10-3mol•L-1的氢氧化钡溶液d L．

则a、b、c、d之间由大到小的关系是：______．

（5）一定温度下，向等体积等物质的量浓度的下 * * 份溶液：①NaOH、②CH3COOH、③CH3COONa分别加等量水，pH变化最小的是______（填编号）．一定温度下，向等体积纯水中分别加入等物质的量的CH3COONa和NaCN，两溶液中阴离子的总物质的量分别为n1和n2，则n1和n2的关系为n1______n2（填“＞”、“＜”或“=”）．

（6）己知常温时Ksp（AgCl）=1.8×10-10mol2．L-2，向50mL 0.018mo1．L-l的AgNO3溶液中加入相同体积0.020mol．L-1的盐酸，则c（Ag+）=______，此时所得混合溶液的pH=______．

答案

（1）①六种盐都为强碱弱酸盐，盐的pH越大，说明对应的酸水解程度越大，则对应的酸越弱，则

A．CH3COOH酸性大于HCN，反应能发生，故A正确；

B．酸性H2CO3＞HClO＞HCO3-，应生成NaHCO3，反应不能发生，故B错误；

C．酸性H2CO3＞HClO＞HCN，应生成NaHCO3，不能生成CO2，故C错误；

D．酸性C6H5OH＞HCO3-，反应能发生，故D正确；

E．酸性H2CO3＞C6H5OH＞HCO3-，反应能发生，故E正确，

故答案为：BC；

②据反应H2B（少量）+2A-=B2-+2HA，可知，HA酸性小于H2B，HA酸性最弱，酸性越弱，对应的酸根离子得H+能力越强，没有HB-生成，说明得电子能力A-大于HB-，则得电子能力顺序为A-＞B2-＞HB-，故答案为：A-＞B2-＞HB-；

（2）各反应均有固体生成，其溶解度更小，故复分解反应能够向生成更难溶的物质的方向进行，

故答案为：由溶解度相对较大的物质向生成溶解度相对较小的物质的方向进行；

（3）溶液中的c（H+）=10-9mol．L-1，说明溶液呈碱性，只有Na2S和NaOH符合，故答案为：CD；

（4）一水合氨为弱电解质，不能完全电离，与盐酸反应至中性时，氨水应稍过量，则b＞a，c（OH -）=1.0×10-3mol．L-l的氨水，一水合氨浓度远大于1.0×10-3mol．L-l的氨水，反应至中性时，a＞c，氢氧化钡为强碱，与盐酸完全中和时，a=d，则b＞a=d＞c，

故答案为：b＞a=d＞c；

（5）CH3COONa为强碱弱酸盐，水解呈碱性，且水解程度较小，加水稀释时，浓度减小同时促进水解，但pH变化不大；向等体积纯水中分别加入等物质的量的CH3COONa和NaCN，NaCN水解程度比大CH3COONa，两种溶液中c（Na+）相等，由于CH3COONa溶液中H+浓度大于NaCN溶液中H+的浓度，则CH3COONa溶液中阴离子浓度较大，

故答案为：③；＞；

（6）向50mL 0.018mo1．L-l的AgNO3溶液中加入相同体积0.020mol．L-1的盐酸，盐酸过量，反应后的c（Cl-）=

0.02mol/L×0.05L-0.018mol/L×0.05L
0.1L
=0.001mol/L，

则c（Ag+）=

Ksp(AgCl)
c(Cl-)
=
1.8×10-10
0.001
mol/L=1.8×10-7 mol/L，

c（H+）=

0.02mol/L×0.05L
0.1L
=0.01mol/L，

pH=2，

故答案为：1.8×10-7 mol/L； 2．

完形填空

第三节完形填空（共20小题；每小题1.5分，满分30）

阅读下面短文，掌握其大意，然后从21--40个选项（A,B,C和D）中，选出最佳选项，并在答题卡上将该选项的标号涂黑。

I left my friend’s house nearly after seven. It was still too early for me to have my evening meal,  _21_  I walked along the sea front for about an hour  _22__  I began to feel hungry. By that time I was not far from a favorite restaurant of mine,  _23__  I often went to eat. I went into the restaurant and  _24_  my meal. While I was waiting for the soup  _25_  I looked around to see if I knew anyone in the restaurant. It was then  _26_  I noticed that a man seated at a corner table kept glancing  _27_  my direction, as if he knew me. The man had a newspaper in front of him, which he was  _28_  to read. When the waiter  _29_  my soup, the man was clearly puzzled by the  _30__  way in which the waiter and I addressed (称呼) each other. He became more  _31_  as time went on and it was  _32_  that I was well known in the restaurant. Eventually, he stood up and went into the  _33__ . After a few minutes he came out again,  _34_  the bill and left. Then I called the owner of the restaurant and asked him  _35_  the man had wanted. At first the owner did not want to tell me, but I  _36__ . “Well,” he said. “That man was from the police.” “Really?” I said, considerably surprised. “He was very  _37_  you.” “But why?” I asked. “He  _38_  you here because he thought you were the man he was  _39__ ,” the owner said. “When he came into the kitchen, he showed me a photograph of the  _40__ . Of course, it was you.”

21. A. and            B. but                 C. so                   D. yet

22. A. until             B. when                C. because               D. after

23. A. where            B. what                C. which             D. that

24. A. sent              B. ordered              C. carried            D. got

25. A. making         B. to arrive           C. carrying          D. prepared

26. A. that             B. when             C. who                D. which

27. A. back             B. in                  C. off               D. at

28. A. trying           B. pretending               C. holding            D. going

29. A. brought          B. fetched               C. sent               D. took

30. A. familiar             B. strange               C. interesting          D. easy

31. A. puzzled          B. interested          C. funny             D. impatient

32. A. obvious          B. known               C. difficult            D. impossible

33. A. office            B. restaurant        C. kitchen           D. WC

34. A. gave             B. sent                 C. paid                    D. ordered

35. A. how             B. that                 C. which             D. what

36. A. thought          B. said                 C. explained          D. insisted

37. A. excited at     B. worried about       C. satisfied with        D. interested in

38. A. searched          B. followed            C. persuaded         D. advised

39. A. finding          B. looking for        C. talking to           D. listening to

40. A. wanted man      B. owner               C. policeman         D. waiter
查看答案
单项选择题

下列关于总账的说法，正确的是（）。

A．总账是根据总账科目开设的账簿

B．总账一般使用活页账

C．总账一般逐日逐笔登记

D．应付款项的备查簿也属于总账
查看答案