问题 填空题

5种固体物质A、B、C、D、E由下表中不同的阴阳离子组成,它们均易溶于水。

阳离子Na+  Al3+   Fe3+  Cu2+、 Ba2+
阴离子OH Cl CO32 NO3 SO4
 

分别取它们的水溶液进行实验,结果如下:

①A溶液与C溶液混合后产生蓝色沉淀,向该沉淀中加入足量稀HNO3,沉淀部分溶解,剩余白色固体;

②B溶液与E溶液混合后产生红褐色沉淀,同时产生大量气体;

③少量C溶液与D溶液混合后产生白色沉淀,过量C溶液与D溶液混合后无现象;

④B溶液与D溶液混合后无现象;

⑤将38.4 g Cu片投入装有足量D溶液的试管中,Cu片不溶解,再滴加1.6 mol·L-1稀H2SO4,Cu逐渐溶解,管口附近有红棕色气体出现。

(1)据此推断A、C的化学式为:A             ;C             

(2)写出步骤②中发生反应的化学方程式                                   

(3)D溶液中滴入石蕊试液,现象是                                          

原因是                                            (用离子方程式说明)。

(4)步骤⑤中若要将Cu片完全溶解,至少加入稀H2SO4的体积是               mL。

(5)现用500 mL 3 mol·L-1的E溶液充分吸收11.2 L CO2气体(标准状况 下),反应后溶液中各离子的物质量浓度由小到大的顺序为                                

(6)若用惰性电极电解A和B的混合溶液,溶质的物质的量均为0.1 mol,请在坐标系中画出通电后阳极产生气体的体积(标准状况下)V与通过电子的物质的量n的关系(不考虑气体溶于水)。

答案

(1)CuSO4  Ba(OH)2(各1分)

(2)2FeCl3+3Na2CO3+3H2O=2Fe(OH)3↓+3CO2↑+6NaCl(2分)

(3)溶液由无色变成红色(2分) Al3++3H2OAl(OH)3+3H+(2分)  

(4)500(2分)

(5)c(H+)<c(OH)<c(CO32)<c(HCO3)<c(Na+)(2分)

(6)(2分)

题目分析:由①知,A、C反应产生的沉淀中应是氢氧化铜和硫酸钡沉淀;则A、C是CuSO4、Ba(OH)2中的一种;由②知,B、E只能是盐类,双水解产生气体和沉淀,其中含有Fe3+、CO32,且其中必有Na2CO3;由③知C为强碱,所以C是Ba(OH)2,A是CuSO4;D为铝盐;由②④知,E为Na2CO3;由⑤知D中有NO3,所以D为Al(NO3)3,则B只能为FeCl3

(1)A、C的化学式为:CuSO4、Ba(OH)2

(2)步骤②是Fe3+、CO32的双水解反应,化学方程式为2FeCl3+3Na2CO3+3H2O=2Fe(OH)3↓+3CO2↑+6NaCl;

(3)Al(NO3)3溶液由于Al3+水解而是溶液显酸性,所以加入石蕊试液,溶液变红色,离子方程式为Al3++3H2OAl(OH)3+3H+

(4)根据Cu与稀硝酸反应的离子方程式3Cu+8H++2N3-=3Cu2++2NO↑+4H2O,得3Cu~8H+,38.4 g Cu的物质的量为0.6mol,所以需要硫酸的物质的量是0.8,其体积为500mL;

(5)由题意知n(CO2)=0.5mol,n(Na2CO3)=1.5mol,所以二者反应后溶液中有1mol的NaHO3,1mol的Na2CO3

Na2CO3水解程度大于NaHO3水解程度,所以溶液中离子浓度由小到大的顺序为c(H+)<c(OH)<c(CO32)<c(HCO3)<c(Na+)(2分)

(6)阳极先是Cl-放电,溶液中共有0.3mol Cl-,根据2 Cl- +2 e-= Cl2↑,得转移电子0.3mol时产生气体标准状况下的体积是3.36L;然后是氢氧根离子放电,4OH--4 e-=O2↑+2H+,每转移0.1mol电子就生成0.56L的气体,所以图像如下:

阅读理解

任务型阅读。

     Many North Americans love sport. This does not necessarily mean that they get any exercise . What

they do is watch national teams on television. They watch baseball, football , basketball, hockey, golf and

tennis-which means that for most of the weekends they sit in front of the television.(4)they  are  watch  

with them.  their friends  If  friendly

     Baseball is the great American sport and every team has fans. Nearly every big city has a team , and

as each team plays. 162 games a year, following baseball can take up a lot of time. The playing season

begins in spring and finishes in the fall World series, when the two leading teams play each other. The first

to win four games wins the Serries. Although called the World Series, Canada is the only other country to

take part in it.

     Football ,played in the fall and winter , is also very popular. It is not at all like the game called soccer.

There isn’t much kicking in American football, which has more to do with running with the ball and

knocking people down. Each team only plays 16 games during the season, and these take place on

Sundays and Monday evenings . (5)Half the country watches the final game on a Sunday , in

January.

     When there are no good games on television , Americans watch college sports. Many colleges feel

that if they want their former students to give money to their old schools, they need a winning football

team. To our surprise , this seems to be true.

Answer the following questions according to passage.

1. When do Americana and their friends sit to watch games on TV?

                                                        _    

2. How many countries are there in the World Series?

_______________________________

3. Why are college teams important for colleges in America ?

                                                              

4. 连词成句

_______________________________

5. 句子翻译

_______________________________

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