参考KNO3的部分溶解度，进行了如图实验操作（每步均充分溶解）．下列说法不正确的是（　　）

A:KNO3的溶解度受温度变化影响大

B:在实验操作过程中只有A是饱和溶液

C:实验操作B到C过程中有晶体析出

D:实验操作中溶质质量分数最大的是B

打气筒是一种空气泵，通过抽拉方式，先将空气吸入储藏部位，然后注入轮胎中．如图是一款打气筒示意图．

（1）图中所示材料中，属于金属材料的是　 　（写出一种即可，下同），属于有机合成材料的是　 　．

（2）空气中氮气的体积分数约为　 　，其化学性质稳定，故常用作　 　．

（3）铸铁是由铁、碳和硅等物质组成的合金，写出碳在氧气中完全燃烧的化学方程式　 　．

解：（1）铝合金和铸铁都属于金属材料，塑料和橡胶都属于有机合成材料，故填：铝合金；塑料；

（2）空气中氮气的体积分数约为78%，其化学性质稳定，故常用作食品保护气，故填：78%；保护气．

（3）碳在空气中完全燃烧生成二氧化碳，反应物是碳和氧气，生成物是二氧化碳，所以方程式是：C+O2[590fcce36099dfee.png]CO2；

答案：

（1）铝合金；塑料；

（2）78%；保护气；

（3）C+O2[8247f619b1405cc2.png]CO2；

近一年的化学学习，你已经掌握了实验室制取气体的有关方法．回答下列问题

（1）仪器①的名称是　 　．

（2）A装置除可用作实验室制取H2、O2的发生器外，还可以用作制取　 　气体的发生装置．

（3）A装置可用于实验室制取H2，反应的化学方程式是　 　，如何检查A装置气密性？　 　．

（4）对制取氢气的装置进行了改进，用大小不同的两只试管设计了B、C装置，准备用于制取少量H2，你认为B、C装置中哪一种装置更好　 　（填序号），原因是　 　．

解：（1）长颈漏斗方便加液体药品，故答案为：长颈漏斗；

（2）A装置除可用作实验室制取H2、O2的发生器外，还可以用作制取二氧化碳，因为实验室制取CO2，是在常温下，用大理石或石灰石和稀盐酸制取的，碳酸钙和盐酸互相交换成分生成氯化钙和水和二氧化碳，因此不需要加热；故答案为：二氧化碳；

（3）实验室是用锌粒和稀硫酸在常温下反应制氢气的，同时生成硫酸锌；检查A装置气密性的方法是：橡皮管用止水夹夹住，从长颈漏斗中倒入水至淹没下端管口，使长颈漏斗中形成一段水柱，过一会儿，水柱不下降证明气密性良好；故答案为：Zn+H2SO4＝ZnSO4+H2↑；橡皮管用止水夹夹住，从长颈漏斗中倒入水至淹没下端管口，使长颈漏斗中形成一段水柱，过一会儿，水柱不下降证明气密性良好；

（4）对制取氢气的装置进行了改进，用大小不同的两只试管设计了B、C装置，准备用于制取少量H2，我认为B装置更好，因为更有利于空气的排出；故答案为：B；更有利于空气的排出；

以工业大理石（主要杂质是氧化铁）为原料提纯碳酸钙的流程如图

（1）为加快反应①的速率，可以采取的措施是　 　．

（2）操作a的名称为　 　，在实验室里进行此操作，将滤纸紧贴漏斗内壁的原因是　 　．

（3）写出反应②的化学反应方程式　 　，其基本反应类型是　 　．

（4）碳酸钙在生活、生产中有着广泛的应用，请写出一种碳酸钙在生活中的用途　 　．

解：（1）增大反应物的接触面积能加快反应①的速率，可以采取的措施是将大理石粉碎．

（2）操作a是将溶液与滤渣分离，操作a的名称是过滤．在实验室里进行此操作，将滤纸紧贴漏斗内壁的原因是防止出现气泡，影响过滤速率．

（3）反应②，即反应①生成的氯化钙与碳酸钠溶液反应生成碳酸钙沉淀和氯化钠，反应的化学方程式为：CaCl2+Na2CO3═CaCO3↓+2NaCl；该反应是两种化合物相互交换成分生成两种新的化合物的反应，属于复分解反应．

（4）碳酸钙在生活中可用作补钙剂（合理即可）．

故答案为：（1）将大理石粉碎；（2）过滤；防止出现气泡，影响过滤速率；（3）CaCl2+Na2CO3═CaCO3↓+2NaCl；复分解反应；（4）用作补钙剂（合理即可）．

某研究小组发现，原本银白色有金属光泽的镁，露置在空气中一段时间后，表面覆盖一层黑色物质．该小组同学进行了如下探究

探究一：灰黑色物质成分

【猜想与假设】小明说灰黑色可能含有MgO、Mg（OH）2、Mg2（OH）2CO3．

小芳说：不可能是MgO，原因是　 　．

【进行实验】

【得出结论】由实验可知，灰黑色物质中一定含有　 　；写出实验②中发生的化学方程式　 　．

探究二：产生灰黑色物质的原因

在猜想产生灰黑色物质的原因时，小华认为镁条变黑与N2无关，其理由是　 　．为进一步探究产生灰黑色物质的原因，设计如图实验，其中NaOH溶液的作用是　 　，经过一段时间，试管中镁条基本无变化．

【得出结论】镁表面的黑色物质是镁与空气中O2、CO2、H2O共同作用的结果

【实验拓展】（1）用镁条实验前一般要进行的操作是　 　．

（2）保存镁条的方法是　 　．

解：探究一：

【猜想与假设】

不可能是MgO，原因是氧化镁是白色固体．

故填：氧化镁是白色固体．

【得出结论】

由实验可知，灰黑色物质中一定含有Mg2（OH）2CO3，这是因为Mg2（OH）2CO3能和稀盐酸反应生成氯化镁、水和二氧化碳；

实验②中二氧化碳和氢氧化钙反应生成碳酸钙沉淀和水，发生的化学方程式为：Ca（OH）2+CO2═CaCO3↓+H2O．

故填：Mg2（OH）2CO3；Ca（OH）2+CO2═CaCO3↓+H2O．

探究二：

在猜想产生灰黑色物质的原因时，小华认为镁条变黑与N2无关，其理由是氮气化学性质不活泼，通常情况下不能和镁反应；

为进一步探究产生灰黑色物质的原因，设计如图实验，其中NaOH溶液的作用是吸收空气中的二氧化碳，防止二氧化碳和镁接触，经过一段时间，试管中镁条基本无变化，说明镁表面变黑色需要二氧化碳参加．

故填：氮气化学性质不活泼，通常情况下不能和镁反应；吸收空气中的二氧化碳，防止二氧化碳和镁接触．

【实验拓展】

（1）用镁条实验前一般要进行的操作是打磨，以除去表面的物质．

故填：打磨．

（2）因为通常情况下镁能和空气的物质发生反应，因此保存镁条的方法是隔绝空气．

故填：隔绝空气．

日常生活中常采用煮沸方法将硬水软化，这种方法一定可靠吗？

【查阅资料】水的硬度是由水中所溶解的可溶性钙、镁化合物引起的，硬水中所溶解的钙、镁化合物可分为两类：钙、镁的碳酸氢盐，如Ca（HCO3）2等；钙、镁的硫酸盐或氯化物，如CaCl2等，一般所说水的硬度是由上述两类化合物引起的．

【设计并实验】小明为方便研究准备了碳酸氢钙溶液和氯化钙溶液来代表两类不同的钙、镁化合物

【得出结论】煮沸实际上只能降低　 　所引起的水的硬度．实验中A试管中碳酸氢钙分解除产生沉淀外，还生成了另外两种氧化物，请写出反应的化学方程式　 　．

【评价与反思】（1）小芳同学提出，若向碳酸氢钙溶液中滴加少量酚酞溶液，溶液变为红色，则说明　 　．

（2）在实验室中一般可通过　 　来降低水的硬度，硬水会给我们的生活和生产带来很多危害，请写出一种　 　．

【实验拓展】向澄清石灰水中持续通入CO2气体，会得到Ca（HCO3）2溶液，利用pH传感器测定在此操作过程中pH变化曲线如图所示：请写出两条结论

（1）　 　；（2）　 　．

解：【得出结论】根据题中信息，A试管中有大量的泡沫，B试管中泡沫较少，说明加热后，A试管中水的硬度降低了，而B试管中水的硬度没有降低，因此煮沸实际上只能降低钙、镁的碳酸氢盐类所引起的水的硬度，故填：钙、镁的碳酸氢盐．

实验①中A试管中碳酸氢钙分解除产生沉淀碳酸钙外，还生成了另外两种氧化物，由质量守恒定律反应前后元素种类不变，另外两种氧化物应是水和二氧化碳，因此反应的化学方程式为：Ca（HCO3）2[cb20cf91e82db0cb.png]CaCO3↓+CO2↑+H2O，故填：Ca（HCO3）2[48441588d4ae7867.png]CaCO3↓+CO2↑+H2O．

【评价与反思】向碳酸氢钙溶液中滴加少量酚酞溶液，溶液变为红色，则说明碳酸氢钙的水溶液呈碱性，故填：碳酸氢钙的水溶液呈碱性；

在实验室可用蒸馏的方法来降低水的硬度，硬水会给我们的生活和生产带来很多危害，例如用硬水洗衣物既浪费肥皂，也洗不净衣物，故填：蒸馏；用硬水洗衣物既浪费肥皂，也洗不净衣物．

【实验拓展】（1）硬水中Ca（HCO3）2是由自然界中的CaCO3遇水和CO2的条件下反应生成的，因此某同学向澄清石灰水中持续通入CO2气体，观察到的现象是起初石灰水变浑浊，之后又逐渐变得澄清，故填：起初石灰水变浑浊，之后又逐渐变得澄清．

（2）根据图示可以看出，溶液的pH是逐渐减小到接近7的，故氢氧化钙的碱性强于碳酸氢钙，故填：氢氧化钙的碱性强于碳酸氢钙．

一定质量的氯化钡溶液和10g溶质质量分数为9.8%的稀硫酸恰好完全反应后，过滤得到28.47g滤液．请计算：

（1）生成硫酸钡沉淀的质量；

（2）氯化钡溶液的溶质质量分数．

解：参加反应的硫酸的质量为10g×9.8%＝0.98g

设生成硫酸钡的质量为x，参加反应的氯化钡的质量为y．

BaCl2+H2SO4═BaSO4↓+2HCl

208 98 233

y 0.98g x

[92197bba242ff6fc.png]＝[ddc9cad463ac02ae.png]＝[a2797fcc3775cfd5.png]

x＝2.33g y＝2.08g

氯化钡溶液的溶质质量分数[e881c8bb6aa0b7f2.png]×100%＝10%

答：（1）生成硫酸钡沉淀的质量2.33g；

（2）氯化钡溶液的溶质质量分数为10%．

My Favourite Books

Jo Usmar is a writer for Cosmopolitan and co﹣author of the This Book Will series（系列） of lifestyle books． Here she picks her top reads．

Matilda

Roald Dahl

I once wrote a paper on the influence of fairy tales on Roald Dahl's writing and it gave me a new appreciation for his strange and delightful worlds． Matilda's battles with her cruel parents and the bossy headmistress， Miss Trunchbull， are equally funny and frightening， but they're also aspirational．

After Dark

Haruki Murakami

It's about two sisters ﹣Eri， a model who either won't or can′t stop sleeping， and Mari， a young student． In trying to connect to her sister， Mari starts changing her life and discovers a world of diverse "night people" who are hiding secrets．

Gone Girl

Gillian Flynn

There was a bit of me that didn′t want to love this when everyone else on the planet did，but the horror story is brilliant． There's tension and anxiety from the beginning as Nick and Amy battle for your trust． It's a real whodunit and the frustration when you realise what's going on is horribly enjoyable．

The Stand

Stephen King

This is an excellent fantasy novel from one of the best storytellers around． After a serious flu outbreak wipes out 99.4% of the world′s population， a battle unfolds between good and evil among those left． Randall Flagg is one of the scariest characters ever．

（1）Who does "I" refer to in the text？　C　

A．Stephen King．

B．Gillian Flynn．

C．Jo Usmar．

D．Roald Dahl．

（2）Which of the following tells about Mari and Eri？　C　

A．Cosmopolitan．

B．Matilda．

C．After Dark．

D．The Stand．

（3）What kind of book is Gone Girl？　D　

A．A folk tale．

B．A biography．

C．A love story．

D．A horror story．

1．C． 细节理解题．根据文章第一段 Jo Usmar is a writer for Cosmopolitan and co﹣author of the This Book Will series（系列） of lifestyle books乔•乌斯玛是"世界主义者"的作家，也是这本书"威尔系列"（系列）的作者之一．可知文本中"我"指的是 Jo Usmar；故选C．

2．C． 细节理解题．根据文章第三段It's about two sisters ﹣Eri， a model who either won't or can′t stop sleeping， and Mari， a young student可知在__之讲述了Mari和Eri；故选C．

3．D． 细节理解题．根据文章第四段 There's tension and anxiety from the beginning as Nick and Amy battle for your trust． It's a real whodunit and the frustration when you realise what's going on is horribly enjoyable可知一个__故事是属于Gone Girl的；故选D．

"You can use me as a last resort（选择）， and if nobody else volunteers， then I will do it．"This was an actual reply from a parent after I put out a request for volunteers for my kids' lacrosse（长曲棍球） club．

I guess that there's probably some demanding work schedule， or social anxiety around stepping up to help for an unknown sport． She may just need a little persuading． So I try again and tug at the heartstrings． I mention the single parent with four kids running the show and I talk about the dad coaching a team that his kids aren't even on…At this point the unwilling parent speaks up，"Alright． Yes，I'll do it．"

I'm secretly relieved because I know there's real power in sharing volunteer responsibilities among many．The unwilling parent organizes the meal schedule，sends out emails，and collects money for end﹣of﹣season gifts． Somewhere along the way，the same parent ends up becoming an invaluable member of the team．The coach is able to focus on the kids while the other parents are relieved to be off the hook for another season． Handing out sliced oranges to bloodthirsty kids can be as exciting as watching your own kid score a goal．

Still， most of us volunteers breathe a sigh of relief when the season comes to a close．That relief is coupled with a deep understanding of why the same people keep coming back for more： Connecting to the community （社区） as you freely give your time， money， skills，or services provides a real joy． Volunteering just feels so good．

In that sense， I'm pretty sure volunteering is more of a selfish act than I'd freely like to admit． However， if others benefit in the process， and I get some reward too， does it really matter where my motivation lies？

（1）What can we infer about the parent from her reply in paragraph 1？　C　

A． She knows little about the club．

B． She isn't good at sports．

C． She just doesn't want to volunteer．

D． She's unable to meet her schedule．

（2）What does the underlined phrase"tug at the heartstrings"in paragraph 2 mean？　B　

A． Encourage teamwork．

B． Appeal to feelings．

C． Promote good deeds．

D． Provide advice．

（3）What can we learn about the parent from paragraph 3？　D　

A． She gets interested in lacrosse．

B． She is proud of her kids．

C． She'll work for another season．

D． She becomes a good helper．

（4）Why does the author like doing volunteer work？　B　

A． It gives her a sense of duty．

B． It makes her very happy．

C． It enables her to work hard．

D． It brings her material rewards．

1．C． 细节理解题．根据文章第一段You can use me as a last resort（选择）， and if nobody else volunteers， then I will do it可知从她在第1段的回答中我们可以推断出她只是不想做志愿者；故选C．

2．B． 细节理解题．根据文章第二段So I try again and tug at the heartstrings． I mention the single parent with four kids running the show and I talk about the dad coaching a team that his kids aren't even on…所以我再试一次感情用事了．我提到有四个孩子的单亲家长在主持这个节目，我还谈到爸爸在指导一个团队，他的孩子甚至不在…上．可知意为感情用事；故选B．

3．D． 细节理解题．根据文章第三段The unwilling parent organizes the meal schedule，sends out emails，and collects money for end﹣of﹣season gifts可知我们能从第3段中了解到她成为一个好帮手；故选D．

4．B． 细节理解题．根据文章最后一段 I'm pretty sure volunteering is more of a selfish act than I'd freely like to admit． However， if others benefit in the process可知作者喜欢做志愿者工作它使她非常快乐；故选B

Marian Bechtel sits at West Palm Beach's Bar Louie counter by herself， quietly reading her e﹣book as she waits for her salad．What is she reading？ None of your business! Lunch is Bechtel's "me" time．And like more Americans，she's not alone．

A new report found 46 percent of meals are eaten alone in America． More than half（53 percent）have breakfast alone and nearly half（46 percent）have lunch by themselves．Only at dinnertime are we eating together anymore，74 percent，according to statistics from the report．

"I prefer to go out and be out．Alone，but together，you know？" Bechtel said，looking up from her book．Bechtel，who works in downtown West Palm Beach，has lunch with coworkers sometimes，but like many of us，too often works through lunch at her desk．A lunchtime escape allows her to keep a boss from tapping her on the shoulder．She retuns to work feeling energized．"Today，I just wanted some time to myself，"she said．

Just two seats over，Andrew Mazoleny，a local videographer，is finishing his lunch at the bar．He likes that he can sit and check his phone in peace or chat up the barkeeper with whom he's on a first﹣name basis if he wants to have a little interaction（交流）． "I reflect on how my day's gone and think about the rest of the week，"he said，"It's a chance for self﹣reflection．You return to work recharged and with a plan．"

That freedom to choose is one reason more people like to eat alone．There was a time when people may have felt awkward about asking for a table for one，but those days are over．Now，we have our smartphones to keep us company at the table．"It doesn't feel as alone as it may have before all the advances in technology，" said Laurie Demeritt，whose company provided the statistics for the report．

（1）What are the statistics in paragraph 2 about？　B　

A．Food variety．

B．Eating habits．

C．Table manners．

D．Restaurant service．

（2）Why does Bechtel prefer to go out for lunch？　C　

A．To meet with her coworkers．

B．To catch up with her work．

C．To have some time on her own．

D．To collect data for her report．

（3）What do we know about Mazoleny？　D　

A．He makes videos for the bar．

B．He's fond of the food at the bar．

C．He interviews customers at the bar．

D．He's familiar with the barkeeper．

（4）What is the text mainly about？　A　

A．The trend of having meals alone．

B．The importance of self﹣reflection．

C．The stress from working overtime．

D．The advantage of wireless technology．

1．B． 细节理解题．根据文章第二段 More than half（53 percent）have breakfast alone and nearly half（46 percent）have lunch by themselves可知第2段的统计数字是关于饮食习惯的；故选B．

2．C． 细节理解题．根据文章第三段．She retuns to work feeling energized．"Today，I just wanted some time to myself，"she said可知Bechtel喜欢出去吃午餐是为了有点儿自己的时间；故选C．

3．D． 推理判断题．根据文章第四段He likes that he can sit and check his phone in peace or chat up the barkeeper with whom he's on a first﹣name basis if he wants to have a little interaction可知Mazoleny他熟悉酒吧老板；故选D．

4．A． 推理判断题．根据文章最后一段There was a time when people may have felt awkward about asking for a table for one，but those days are over．Now，we have our smartphones to keep us company at the table可知主要内容是独自吃饭的趋势；故选A