（本题包括1小题，共12分）

27.（11分）四硫化钠（Na₂S₄）固体可替代红磷测定空气中氧气的体积分数，反应原理为：2 Na₂S₄ + O₂ + 2H₂O = 8S↓+ 4 NaOH。

【实验资料】

①四硫化钠（Na₂S₄）的相对分子质量为         ，其中硫元素的质量分数为        （结果精确到0.1%）。

②四硫化钠受热时，会与空气中的水蒸气反应，生成少量有毒气体硫化氢。

③NaOH溶液呈碱性，可吸收硫化氢、二氧化碳、二氧化硫等酸性气体

④硫代硫酸钠（Na₂S₂O₃）可溶于水，常温下与NaOH溶液不反应。

【实验过程】

①取碳酸钠、 硫粉混合后置于试管中，加热（如图1所示，夹持装置已略去），制得Na₂S₄，反应为4Na₂CO₃ + 12S + X 2 Na₂S₄+ 2 Na₂S₂O₃ + 4CO₂，X 的化学式为       ，蘸有浓NaOH 溶液的棉花的作用是                                                   。

②冷却后，取下棉花，放置一段时间，再向该试管中加入10ml水，迅速塞紧橡胶塞，充分振荡，测量液面至橡胶塞下沿的距离，记录数据h1（如图2所示）

③将该试管插入水中（如图3所求），取下橡胶塞，观察到                            

                                                          ，塞紧橡胶塞。将试管取出，倒过来，测量液面至橡胶塞下沿的距离，记录数据h2，理论上h1:h2＝         

④按照①～③再重复实验2次．3次实验数据如下表所示。

	第1次	第2次	第3次
h1/cm	11.2	11.4	11.6
h2/cm	8.9	9.1	9.2

 

【解释与结论】根据第1次实验数据，计算空气中氧气的体积分数为       （结果精确到0.1%）。

【反思与评价】(1)若实验过程②中，取下棉花后，未放置一段时间即进行后续操作，会影响测定结果，请说明有何影响，并阐述理由：                               。（2分）

 （2）若要保证实验的效果，至少需要生成四硫化钠（Na₂S₄）0.174g ,则理论上实验时至少取碳酸钠粉末     克？写出计算过程（2分）

 

(12分)
本题共有3个小题，回答有关问题：
(1)检验牙膏中含有甘油的试剂是            ，实验现象           ；有关反应的化学方程式                                  。

(2)在两烧杯中盛有甲、乙两种不同的稀溶液，用铁丝做电化腐蚀实验。实验进行一段时间后，A试管中液面高于烧杯中液面，B试管中液面低于烧杯中液面，试比较pH值大小：
甲     乙(填“<”、“>”或“=”)，并写出A中铁丝发生腐蚀时的电极反应式：负极       ，正极           。
(3)已知某溶液中只存在、H⁺、、Na⁺四种离子，某同学推测其离子浓度大小顺序有如下四种关系：
I：
II：
III：
IV：
①若溶液中只溶解了一种溶质，则该溶质是         ，上述四种离子浓度的大小顺序
为            (填编号)。
②若上述关系中III是正确的，则溶液中溶质为               
③若该溶液是由体积相等的氢氧化钠溶液和醋酸溶液混合而成，且恰好呈中性，则混合前两溶液的物质的量浓度大小关系为       (填“<”、“>”或“=”)，混合前溶液中的          溶液中的 (填“<”、“>”或“=”)。

第三部分：阅读理解（共20小题，共40分）
第一节（共15题, 每小题2分，满分30分）
阅读下列短文，从每题所给的四个选项（A,B,C和D）中，选出最佳选项。                              
A
What secret force drives us into the arms of one person, while pushing us away from another who might appear equally desirable to any fair observer? Of the many factors influencing our idea of the perfect mate, one of the most telling is our “lovemap” ---- a group of messages formed in our brains that describes our likes and dislikes．It shows our preferences in hair and eye color, in voice, smell, body build．It also records the kind of personality that attracts us, whether it’s the warm and friendly type or the strong silent type．In short, we fall for and go after those people who most clearly fit our lovemap．And this lovemap is determined in childhood．By age eight, the pattern for our ideal mate has already begun to float around in our brains．
The mother has special influence on her sons: she not only gives them clues to what they will find attractive in a mate, but also influences how they feel about women in general．So if she is warm and nice, her sons are going to think that’s the way women are．They will likely grow up warm and responsive lovers and also be helpful around the house．
Just as mothers influence their son’s general feelings toward women, fathers influence their daughter’s general feelings about men．If a father lavishes praise on his daughter and shows that she is a worthwhile person, she’ll feel very good about herself in relation to men．But if the father is cold, critical or absent, the daughter will tend to feel she’s not very lovable or attractive．
While the mother determines in large part what qualities attract us in a mate, it’s the father ----- the first male in our lives ----- who influences how we relate to the opposite sex．Fathers have a great effect on their children’s personalities and chances or marriage happiness．
56．What is the proper title for this passage?
A．Why we love who we love           B．What is a lovemap
C．Different influence from parents        D．Ideal mate in the mind
57．A perfect mate is a person who ____．
A．is fair to everyone               B．is the most desirable
C．fits one’s lovemap               D．is perfect in everything
58．If the husband hardly does any housework, ____．
A．his mother must be warm             B．his father must be critical
C．his mother must be cold               D．his wife can’t be attractive
59．The passage leads to a belief that ____．
A．parents’ personalities decides the children’s lovemap
B．mothers have no influence on daughters’ marriage life
C．fathers care more about children’s marriage happiness
D．mothers influence children’s choices of perfect mates

第三部分：阅读理解（共20小题，共40分）
第一节（共15题, 每小题2分，满分30分）
阅读下列短文，从每题所给的四个选项（A,B,C和D）中，选出最佳选项。                              
A
What secret force drives us into the arms of one person, while pushing us away from another who might appear equally desirable to any fair observer? Of the many factors influencing our idea of the perfect mate, one of the most telling is our “lovemap” ---- a group of messages formed in our brains that describes our likes and dislikes．It shows our preferences in hair and eye color, in voice, smell, body build．It also records the kind of personality that attracts us, whether it’s the warm and friendly type or the strong silent type．In short, we fall for and go after those people who most clearly fit our lovemap．And this lovemap is determined in childhood．By age eight, the pattern for our ideal mate has already begun to float around in our brains．
The mother has special influence on her sons: she not only gives them clues to what they will find attractive in a mate, but also influences how they feel about women in general．So if she is warm and nice, her sons are going to think that’s the way women are．They will likely grow up warm and responsive lovers and also be helpful around the house．
Just as mothers influence their son’s general feelings toward women, fathers influence their daughter’s general feelings about men．If a father lavishes praise on his daughter and shows that she is a worthwhile person, she’ll feel very good about herself in relation to men．But if the father is cold, critical or absent, the daughter will tend to feel she’s not very lovable or attractive．
While the mother determines in large part what qualities attract us in a mate, it’s the father ----- the first male in our lives ----- who influences how we relate to the opposite sex．Fathers have a great effect on their children’s personalities and chances or marriage happiness．
56．What is the proper title for this passage?
A．Why we love who we love           B．What is a lovemap
C．Different influence from parents        D．Ideal mate in the mind
57．A perfect mate is a person who ____．
A．is fair to everyone               B．is the most desirable
C．fits one’s lovemap               D．is perfect in everything
58．If the husband hardly does any housework, ____．
A．his mother must be warm             B．his father must be critical
C．his mother must be cold               D．his wife can’t be attractive
59．The passage leads to a belief that ____．
A．parents’ personalities decides the children’s lovemap
B．mothers have no influence on daughters’ marriage life
C．fathers care more about children’s marriage happiness
D．mothers influence children’s choices of perfect mates

（7分）某同学进行试验探究时，欲配制10%的Ba(OH)₂溶液，但只找到在空气中暴露已久的Ba(OH)₂试剂。在室温下配制溶液时发现所取试剂在水中仅部分溶解，烧杯中存在未溶物。为探究原因，该同学查得Ba(OH)₂在20℃时的溶解度2.1 g。

（1）烧杯中未溶物仅为BaCO₃，理由是（用化学方程式表示）                 。

（2）假设试剂由大量Ba(OH)₂和少量BaCO₃组成，设计试验方案，进行成分检验，在答题卡上写出实验步骤、预期现象和结论。

限选试剂及仪器：稀盐酸、稀硫酸、NaOH溶液、澄清石灰水、氯化铜溶液、烧杯、试管、带塞导气管、滴管

实验步骤	预期现象和结论
步骤1：取适量试剂于洁净烧杯中，加入足量蒸馏水，充分搅拌，静置，过滤，得滤液和沉淀。
步骤2：取适量滤液于试管中，滴加稀硫酸。	有  ①  生成，说明有Ba2+
步骤3：取适量步骤1中的沉淀于是试管中，滴加稀盐酸，用带塞导气管塞紧试管，把导气管插入装有澄清石灰水的烧杯中。	试管中有  ② 生成，烧杯中    ③    ，结合步骤2说明沉淀是BaCO3。
步骤4：取适量滤液于试管中，   ④     。	试管中有蓝色沉淀生成，说明有大量的OH—，综合上面步骤可知试剂由大量Ba(OH)2和少量BaCO3组成，假设成立。

（3）在20℃室温下，     （填“能”或“不能”） 配制10%的Ba(OH)₂溶液。

五、计算与分析题（共2小题，共10分）

目前已制得的纯金属只有90余种，但由这些纯金属按一定组成和质量比制得的合金已达几千种。由于合金更容易适合不同的用途，因此被大量应用于日常生活、工农业及科学研究中。结合所学知识，完成27、28题。