问题 填空题

已知A为中学化学中的一种盐,B、C为日常生活中常见的金属.通常条件下D、G为无色无味气体.已知用惰性电极电解A溶液一段时间后,产物只有C、D和E的稀溶液.各物质之间的转化关系如图(部分反应产物已略去).

请回答下列问题:

(1)A的化学式为______.

(2)A溶液与Na2O2反应的总化学方程式为______.

(3)E的稀溶液与F溶液反应的离子方程式为______.

(4)电解100mL盐A的溶液一段时间后,断开电路,取出电极,测得所得到的气体D在标准状况下的体积为5.6mL,则电解后溶液的pH为______.(假设溶液体积不变)

(5)若向100mL盐A的溶液中加入10g金属单质B的粉末,充分搅拌后,过滤,烘干得10.16g固体C.则滤液中溶质的物质的量浓度为______.(假设溶液体积不变)

答案

(1)电解A溶液时产生金属单质C和另外一种气体D,应为电解含氧酸盐溶液,在阴极上析出不活泼金属,则C应为铜,D为氧气,E溶液能与C金属发生氧化还原反应,且E溶液与F溶液也能反应生成无色无味气体G,说明E溶液具有强氧化性,应为硝酸,故A为硝酸,C为铜,D为氧气,G为NO,F与硝酸反应生成NO,说明且含有金属B元素,说明F溶液具有还原性,应为Fe(NO32溶液,B为Fe,H为Fe(NO33,故答案为:Cu(NO32

(2)Na2O2与水加入到Cu(NO32溶液中反应生成NaOH和氧气,NaOH和Cu(NO32反应生成蓝色沉淀2Cu(OH)2,故答案为:2Na2O2+2Cu(NO32+2H2O=2Cu(OH)2↓+4NaNO3+O2↑;

(3)硝酸具有强氧化性,Fe2+具有还原性,二者发生氧化还原反应,故答案为:3Fe2++NO3-+4H+═3Fe3++NO↑+2H2O;

(4)根据电解硝酸铜的电极方程式:

2Cu(NO32+2H2O

 电解 
.
 
2Cu+O2↑+4HNO3

                      22.4L   4mol

                     5.6×10-3L  n

则n=

4×mol×5.6×10-3
22.4L L
=1×10-3mol

所以c(H+)=

10-3mol
0.1L
=0.01mol,故PH=2,故答案为:2;

(5)向盐A溶液中加入金属单质B,反应的化学方程式为:Fe+Cu(NO32═Fe(NO32+Cu,根据差量法计算:

Fe+Cu(NO32═Fe(NO32+Cu△m

    1mol                    8g

    n                      10.16g-10g=0.16g

n=

0.16
8
=0.02mol,所以溶液的浓度为:
0.02mol
0.1L
=0.2mol/L,故答案为:0.2 mol/L.

单项选择题
阅读理解

阅读理解

      Britain is set to face an increase in cold winters, with up to oneinseven hitting the UK with

longer periods of time when temperatures are below freezing, a study has suggested.The

prediction was based on research that found out how low solar activity affected winter weather

patterns.

     However, the researchers were eager to stress that their findings did not suggest that the

region was about to fall suddenly into a "little ice age".The findings appear in the journal

Environmental Research Letters."We could get to the point where oneinseven winters are very cold, as we had at the start of last winter and all through the winter before last."said coauthor

Mike Lockwood, professor of space environment physics at the University of Reading.

Using the Central England Temperature (CET) record, the world's longest instrumental data

series that dates back to 1659,the team said that in general temperatures during recent winters

had been obviously lower than the longerterm temperatures."The mean CET for December,

January and February for the recent relatively cold winters of 2008~2009 and 2009~2010

were 3.50℃ and 2.53℃ respectively," they wrote."However, the mean value for the previous 20 winters had been 5.04℃.The series of lower winter temperatures in the UK during the last three years had raised questions about the probability of more similar, or even colder winters

occurring in the future."

     Last year Professor Lockwood and colleagues published a paper that found a link between

fewer sunspots and atmospheric conditions that "blocked" warm westerly winds reaching

Europe during winter months, opening the way for cold easterly winds from the Arctic and

Russia to sweep across the region.Professor Lockwood, while acknowledging that there were a

range of possible meteorological factors (气象因素) that could influence blocking events, said

the latest study moved things forward by showing that there was "improvement in the predictive skill" when solar activity was taken into consideration.

1. We can know from the second paragraph that ________.

A. research shows that Britain will soon fall into an ice age

B. Mike Lockwood's research focuses on space environment physics

C. it was quite cold in Britain over the entire winter last year

D. so far oneinseven winters have been very cold in Britain

2. The underlined word "mean" in Paragraph 3 is closest in meaning to "________".

A. average  

B. stable

C. ungenerous  

D. changeable

3. What can we infer from the last paragraph?

A. It was sunspots that blocked warm westerly winds reaching Europe.

B. Meteorological factors hardly have any influence on blocking events.

C. The latest study done by Professor Lockwood was of little practical value.

D. Considering solar activity or not affects the accuracy of weather forecasting.

4. What's the best title of the passage?

A. Another Big Danger Approaching the UK

B. Research Finds out Solar Activity Is to Blame for the Cold

C. UK Faces More Cold Winters Due to Weaker Solar Activity

D. Changes in Weather Patterns Should Be Responsible for Low solar Activity