Unit 5 I Love Learning English! Lesson25:A Phone Friend Ⅰ.Learning aims:
1:Grasp main words.
2: Understand important sentences. 3: Can use important grammar. Ⅱ.Learning main points:
1: Grasp words and phrases. 2: Key sentences and structures.
3: Learn about the tips of making phone calls. Ⅲ.Learning difficulties:
1: Grasp words and phrases. 2: Can use important grammar.
3: Learn about the tips of making phone calls. Ⅳ.导学环节: (一) self-learning:
1:温故知新:
(1) I always practice ---(learn)English. (2)They -- -- --(be going to) visit their friends. (3)This one is –(昂贵的),would you like that one.
(4)Look at the –(接着的) examples,and then find the answers by youself.
2:互助释义:
(1) Understand :v 懂得,理解,其过去式和过去分词均为 understood,eg:He understood its meaning at last.
(2) No problem. 没问题。用来表示同意和愉快的回答请求,也可回答感谢,意为“不客气”eg:---Thank you ----No problem.
(3)Could 的用法:
could 用作情态动词,意为“能;可能”是can的过去式,(1) 用来表示过去的能力:She could swim when she was six. 她六岁的时候就会游泳。
a. 表示许可:can和could均可用,但用could 语气更委婉, eg: Can/Could I come
in? 我可以进来吗?
b. 表示推测:对现在或将来的推测,can和could均可用,但can 通常只用于否定句或疑问句中,一般不用于肯定句,而could则可用于肯定句、否定句和疑问句,eg: You could be right. 你可能是对的。
另外:could 还可用于虚拟语气中, 构成could have done 结构表示因过去可以做的事情没有做而感到遗憾惋惜,或者 couldn't have done 表示过去本不该做的事情而做了感到遗憾懊悔等等。eg: I could have stopped them fighting. 我本来可以阻止他们打架的。
3:探究出招:
(1) Can you ---(理解) what I said to you.
(2) Would you like to help me with my English? -------(没问题)。
(3) Can you do it by yourself? I am very busy now. -------(没问题)。 (4) She ------ swim when she was six. 她六岁的时候就会游泳。 (5) You ------be right.(你可能是正确的)。 (二)展示交流: 小组展示:
Make a phone call with your group, then show it separately. (三)拓展提升: 反馈矫正:
(1) Would you like to make friends with -------(外国人)? (2)------(能)you speak it loudly.
(3) I am from ------(加拿大),so I am a -------(加拿大人)。 (4) Can you -------(理解) me? (5) You ------- be right. (四)课堂作业:
1:作业当堂清:做P67 习题。 2:挑战自我:
(1) She ------ be a good student, I guess.
(2) Can you speak it ------(大声地) ,I can not hear you clearly. (五)板书设计: (六)当堂反思:
Lesson 26: Online Phone Calls Ⅰ.Learning aims:
1:Grasp main words.
2: Understand important sentences. 3: Can use important grammar. Ⅱ.Learning main points:
1: Grasp words and phrases. 2: Key sentences and structures.
3: Learn about the tips of making phone calls. Ⅲ.Learning difficulties:
1: Grasp words and phrases. 2: Can use important grammar.
3: Learn about the tips of making phone calls. 导学环节: (一) self-learning:
1:温故知新:
(1) Can you ---(理解) what I said to you.
(2) Would you like to help me with my English? -------(没问题)。 (3) Can you do it by yourself? I am very busy now. -------(没问题)。 (4) She ------ swim when she was six. 她六岁的时候就会游泳。
(5) You ------be right.(你可能是正确的)。 2:互助释义:
(1). proud adj. 自豪的,常用语短语:be proud of“因……而自豪/骄傲;”eg: I’m proud of my son. 我以我儿子为骄傲。
(2). such adj.那么的;这样的
固定用法:such +a/an+ 形容词+名词;such + 形容词+名词的复数/不可数名词,eg: He is such a clever boy. 他是如此聪明的一个孩子。
(3). Alicia is from Russia. 艾丽西萨来自俄罗斯。
be from=come from来自,eg: He’s from China.=He comes from China. 他来自中国。
(4). It’s all thanks to you. 这多亏了你。 thanks to sb. 多亏有某人
thank sb. for doing sth.感谢某人做某事,eg: Thank you for helping me. 谢谢你帮助我。
(5). You did all the hard work yourself. 你独自一人做了所有艰苦的工作。hard work艰苦的工作,hard 是形容词“艰难的;困苦的”work是不可数名词,“工作”;work hard意为“努力地工作(学习)”,work是动词“工作”,hard是副词“努力地”
eg: The boy works hard. 这个男孩学习很努力。
(6). I can’t wait to see you! 我迫不及待地想见你。 can’t wait to do sth.意为“迫不及待地做某事”,eg:
They can’t wait to open their presents. 他们迫不及待地打开他们的礼物。 eg: I can look after myself. 我能照顾自己。
3:探究出招:
(1) Thank you for-----( help)me.
(2) I’m -----(骄傲的 )of my son
(3) You did all the------ ------ (艰苦的工作)hard work yourself.。 (4) The boy ------ ------. 这个男孩学习很努力。 (5) I can’t------ to see you! 我迫不及待地想见你。。 (二)展示交流: 小组展示:
Make a phone call with your group, then show it separately. (三)拓展提升: 反馈矫正:
(1)He is ------(那么的) a clever girl.
(2)Last year ,he took part in an English ------(竞赛). (3)She is ------(自豪的) of her daughter。 (4) I can ------ ------(照看) myself。
(5) They can’t------ to open their presents. 他们迫不及待地打开他们的礼物。 (四)课堂作业:
1:作业当堂清:做练习册一二题。 2:挑战自我:
(1) She is ------(来自) Russia. (2) It is all ------ to you.这多亏了你。 (五)板书设计: (六)当堂反思: Lesson 27:Amazing English
Ⅰ.Learning aims:
1:Grasp main words.
2: Understand important sentences. 3: Can use important grammar. Ⅱ.Learning main points:
1: Grasp words and phrases. 2: Key sentences and structures.
3: Learn about the tips of making phone calls. Ⅲ.Learning difficulties:
1: Grasp words and phrases. 2: Can use important grammar.
3: Learn about the tips of making phone calls. 导学环节: (一)self-learning:
1:温故知新:
(1) Thank you for-----( help)me. (2) I’m -----(骄傲的 )of my son.
(3) You did all the------ ------ (艰苦的工作)hard work yourself.
(4) I can ------ ------(照看) myself. 2:互助释义:
(1). quick adj. 快的;迅速的,其反义词为:slow缓慢的;
副词为:quickly迅速地;快速地,相当于副词fast,eg: Please walk quickly/fast.
请走快点儿。
(2). even adv. 甚至;还;其实
用在比较级前,加强语气,表示程度。意为“(比……)更,还要” eg:This dictionary is even more useful than that one.这本词典比那本更用。
放在它所强调的词、短语或从句前,用来加强语气,表示“即使,甚至连……都”之意,eg: Even he can draw. 即使他也会画画。
(3). There are only 26 letters in English. 英语中只有26个
字母。there be句型表示“某地有某物”,be动词随主语和时态的变化而变化,eg:
There was a meeting yesterday. 昨天有个会议。
(4). You don’t even need to move any letters around.
你甚至不必移动周围的任何一个字母。need to do sth.需要做某事,其中的need是实义动词,意为“需要”,eg: I need to repair my bicycle. 我需要修理我的自 行车。
Important Grammar 反身代词:
I-myself you-yourself
he-himself she-herself it-itself you-yourselves they-themselves we-ourselves
3:探究出招:
(1) Please walk ------ 请走快点。
(2)This dictionary is------(甚至) more useful than that one. (3)There are only 26------(字母) in English. (4) I ------(需要)to repair my bicycle. (5)------(即使)he can draw this picture. (二)展示交流: 小组展示:
Talk about the amazing English, do you know something about amazing English. Discuss with your deskmate. (三)拓展提升: 反馈矫正:
(1)There are only 26------(字母) in English.
(2) You don’t ------need to move any letters around. (3)------ ------(事实上),he is good at learning English. (4)She is a ------(懒惰的)girl,so no one like her.
(5)Maybe one word can make up a ------(句子)。 (四)课堂作业:
1:作业当堂清:做练习册一二题。
2:挑战自我:
(1) I------ to repair my bicycle. 我需要修理我的自行车。 (2)It is all ------ to you.这多亏了你。 (五)板书设计: (六)当堂反思:
Lesson 28 How Do I Learn English? Ⅰ.Learning aims:
1:Grasp main words.
2: Understand important sentences. 3: Can use important grammar. Ⅱ.Learning main points:
1: Grasp words and phrases. 2: Key sentences and structures.
3: Learn about the tips of making phone calls. Ⅲ.Learning difficulties:
1: Grasp words and phrases. 2: Can use important grammar.
3: Learn about the tips of making phone calls. 导学环节: (一) self-learning:
1:温故知新:
(1) There are only 26------(字母) in English.
(2) You don’t ------need to move any letters around. (3) ------ ------(事实上),he is good at learning English.
(4) She is a ------(懒惰的)girl,so no one like her. 2:互助释义:
(1). newspaper n. 报纸,read newspapers“读报”eg: She likes reading newspapers. 她喜欢读报。
(2). mistake n. 错误,make a mistake/make mistakes意为“犯错误”,eg: She often
makes mistakes in the exam. 考试时她经常犯错误。
(3). So I look them up in a
dictionary. 因此我从字典中查阅它们。look up(在词典、参考书中)查阅,代词必须放在中间,名词可放后面 eg: Please look it up in your dictionary. 请在你的字典中查一下它。
(4). I can enjoy myself and learn English at the same time. 我可以在学英语的同时感受到快乐。enjoy oneself =have a great/good time=have fun“玩的高兴;过得愉快”,eg: We enjoyed ourselves=had a great/good time=had fun last night. 昨晚我们玩得很高兴。N 电话用语:接电话时首先要用“Hello! Hi!”“你好”,如果。接电话的正是对方要找的人,则用:Speaking.或This is…speaking. “我就是……”,而不用I’m…;如果想问对方是谁吗?用Is that…?而不用Are you…? 如果想让对方稍等一会儿,可用:Hold on, please. “请稍等.”eg: --- May I speak to Jenny?--- Speaking. / This is speaking. 我就是詹尼。
3:探究出招:
(1) She likes reading ------(报纸).
(2) She often makes------(错误) in the exam. (3). So I -------them ------ in a dictionary.
(4) I can ------myself and learn English at the same time. (5)This is lily ------. (二)展示交流:
小组展示:Communicate with your partner , how do you learn English? Share your ideas with your partner. (三)拓展提升: 反馈矫正:
(1)Read some ------(故事书) when you are free. (2) May I speak to Jenny? ------
(3)------ ------(事实上),he is good at learning English. (4)She is a ------(懒惰的)girl,so no one like her.
(5) Maybe one word can make up a ------(句子)。 (四)课堂作业:
1:作业当堂清:做练习册一二题。
2:挑战自我:(1) I need to repair my bicycle. 我需要修理我的自行车。 (2) It is all ------ to you.这多亏了你。 (五)板书设计: (六)当堂反思:
Lesson29: A door to the world
Ⅰ.Learning aims:
1:Grasp main words.
2: Understand important sentences. 3: Can use important grammar. Ⅱ.Learning main points:
1: Grasp words and phrases. 2: Key sentences and structures.
3: Learn about the tips of making phone calls. Ⅲ.Learning difficulties:
1: Grasp words and phrases. 2: Can use important grammar.
3: Learn about the tips of making phone calls. Ⅳ.导学环节: (一) self-learning:
1:温故知新:
(1)She likes reading ------(报纸). (2)Can you ---(理解) what I said to you. (3)She often makes------(错误) in the exam.
(4)I can ------myself and learn English at the same time. 助释义:
(1)All over the world,全世界,固定短语,e g. 2:互I want
to travel all over the world.
(2) It takes time, 学英语要花费时间,It takes times to do sth, eg, It takes times to finish my homework.
(3)Opportunity,机会,机遇,eg, New language give them new opportunity.
(4)Challenge:挑战。eg: Learning a new language can be a challenge. 3:探究出招:
(1) Jenny is a good student. She will have a good ------(将来) (2) I------ ------(交流)my foreign friend over the Internet.
(3)He is sick. He must stay home. He can not go ------(任何地方)。 (4) I ------(从不) walk to school , I live too far away.
(5)I got lost on my way to the bookstore. So I went to a policeman and ------ ------(寻求) help. (二)展示交流:
小组展示: Talk about the importance of learning English with your partner . (三)拓展提升:
反馈矫正:According to the meanings and guess words.
(1)A good chance for success. ------ (2)Something difficult or not easy to do.------
(3)A piece of writing in a newspaper or magazine.------ (4)Facts and ideas learned from study and experience.------ (5) Things that are not the same.------
(四)课堂作业:
1:作业当堂清:做P67 习题。 2:挑战自我:
(1) English helps you ------ (交流) people from all over the world. (2) Learning a new language can be a ------(挑战) (五)板书设计: (六)当堂反思:
Lesson30: Writing an E-mail in English Ⅰ.Learning aims:
1:Grasp main words.
2: Understand important sentences. 3: Can use important grammar. Ⅱ.Learning main points:
1: Grasp words and phrases. 2: Key sentences and structures.
3: Learn about the tips of making phone calls. Ⅲ.Learning difficulties:
1: Grasp words and phrases. 2: Can use important grammar.
3: Learn about the tips of making phone calls. Ⅳ.导学环节: (一) self-learning:
1:温故知新:
(1)Jenny is a good student. She will have a good ------(将来) (2)I------ ------(交流)my foreign friend over the Internet.. (3)He is sick. He must stay home. He can not go ------(任何地方). (4)I ------(从不) walk to school , I live too far away. 2:互助释义:
(1)Live with sb, eg: I live with my mother and father. (2) Play chess,下象棋.
(3)Favourite,最喜欢的,最爱的。Eg: My favourite subject is English . (4)Try to do sth . 试着做。。。 3:探究出招:
(1) I like to ------ ------ with my friends. It is a fun game. (2)Please write soon. I am------ ------(期盼,期望) your reply. (3)I ------ ------(试着做…) Call him, but his phone was off. (4) I ------(从不) walk to school , I live too far away. (5)I ------ ------ ------(获得第一名) in the English competition. (二)展示交流:
小组展示: Talk about “What is Wang Mei trying to do in her e-mail?” (三)拓展提升:
反馈矫正:Listen and write true(T) or false(F)
(1)Jessica is from Canada.( )
(2)This is Wang Meiˊs second e-mail to Jessica.( )
(3)Wang Mei has no brothers or sisters.( )
(4)Wang Mei wants to have some more English-speaking friends.( )(5)Wang Mei sends a photo to Jessica in her e-mail.( ) (四)课堂作业:
1:作业当堂清:做P67 习题。 2:挑战自我:
(1) Let me ------(介绍)myself。
(2)I am looking ------(期盼) to your reply. (五)板书设计: (六)当堂反思:
1.2 一定是直角三角形吗
基础导练
1.已知一个三角形的三边分别为3k ,4k ,5k (k为自然数),则这个三角形为 ,理由是 .
2.有一个三角形的两条边长是6和10,要使这个三角形成为直角三角形,则第三边边长为 .
3.已知在?ABC中,BC=6,BC边上的高为4,若AC=5,则AC边上的高为 . [%@~^&]
4.若一个三角形的一个角等于其他两个角的差,那么这个三角形是 三角形. [^@&~#]
5.若一个三角形的三边长为m+1 ,m+2 ,m+3,当m 时,此三角形是直角三角形. [#~^@%]
6.已知?ABC的三边长为BC=41,AC=40,AB=9,则?ABC为_________三角形,最大角是∠ .
7.以?ABC的三条边向外作正方形,依次得到的面积为25,144,169, 则这个三角形是________三角形. [&~@*#]
8.三角形各边(从小到大)长度的平方比如下列各组,其中不是直角三角形的是 ( )
A.1∶1∶2 B.1∶3∶4 C.9∶25∶26 D.25∶144∶169
9.下列各组数中,以a,b,c为边长的三角形不是直角三角形的是( )
A.a=1.5,b=2,c=3 C.a=6,b=8,c=10
B.a=7,b=24,c=25 D.a=3,b=4,c=5
10.如图,有一块四边形地ABCD,∠B=90°,AB=4m,BC=3m,CD=12m,DA=13m,求该四边形地ABCD的面积? [@~%&*]
[~&@%^]
211.如图,在四边形ABCD中,AC?DC,△ADC的面积为30cm,DC=12 cm,AB=3 cm, BC=4 cm,求△ABC的面积.
DCBA [~#&%*]
能力提升
12.如图:为修通铁路需凿通隧道AC,测得∠A=50°,∠B=40°,AB=5km,BC=4km,若每天开凿隧道0.3km,试计算需要几天才能把隧道AC凿通?
CAB
[&~%^*]
13.如图,古埃及人用下面方法画直角:把一根长绳打上等距离的13个结,然后用桩钉如图那样钉成一个三角形,其中一个角便是直角,说明这种做法的根据.
(1)(2)(3)(4)(13)(12)(11)(10)(1)(5)(6)(9)(7)(8)
[&~@*%]
14.初春时分,两组同学到村外平坦的田野中采集植物标本,分手后,他们向不同的方向前进,第一组的速度是30米/分,第二组的速度是40米/分,半小时后两组同学同时停下来,而此时两组同学相距1500米.
(1)两组同学行走的方向是否成直角? [%&~@^]
(2)如果接下来两组同学以原速相向而行,多长时间后能相遇?
[~@#*&]
115.已知:如图,△ABC中,CD?AB,垂足为D,且平分AB,CD=2AB,△ABC是等腰直角三角形吗?为什么?请你与同伴交流,并说明理由.
[^*@%#]
16.四年一度的国际数学家大会会标如图甲.它是由四个相同的直角三角形与中间的小正方形拼成的一个大正方形.若大正方形的面积为13,每个直角三角形两条直角边的和是5.
(1)求中间小正方形的面积.
(2)现有一张长为6.5cm、宽为2cm的纸片,如图乙,请你将它分割成6块,再拼合成一个正方形.(要求:先在图乙中画出分割线,再画出拼成的正方形并表明相应数据)
[~@^%&] [@*#&^] [~*@]
参考答案 [#*^~%]
2221.直角三角形;9k+16k=25k 2.8或234 3.4、8 4.直角 5.m
=2 6.直角、90° 7.直角 8.C 9.A 10.四边形地ABCD的面积为36 cm 11.S△ABC=6 cm 12.10天 13.3+4=5,应用勾股定理逆定理得直角三角形 14.(1)是.提示:(30×30)+(40×30)=(50×30);
22222222150222(30×30)+(40×30)=1500;(2)7分钟
15.是.提示:∵BD=AD=DC,CD⊥AB ∴∠A=∠B=45°=∠BCD=∠ACD ∴BC=AC ∠BCA=90°
16.提示:(1)小正方形的面积为1;(2)分割成四个直角三角形和两个小长方形 [@#~&^]
课时分层作业(十三) 如何选择家居装修材料
(建议用时:40分钟) [基础达标练]
1.陶瓷和水泥材料是家庭进行装修时经常会用到的材料。下列关于陶瓷和水泥的说法中正确的是( )
①陶瓷制品中的瓷砖坚硬、耐磨、耐水,不会腐蚀霉变,便于清洗 ②制备陶瓷的三种主要原料的主要成分均为硅酸盐类物质 ③水泥、沙子和水的混合物叫水泥沙浆,是建筑用黏合剂 ④在水泥沙浆中添加适量的水玻璃可以提高水泥沙浆的黏结性和胶凝性
A.①② C.②④
B.②③ D.①③④
D [厨房、卫生间的地面和墙面宜采用瓷砖装修,是因为瓷砖坚硬、耐磨、耐水,不会腐蚀霉变,便于清洗,①正确。制备陶瓷的三种主要原料为黏土、长石、石英,黏土是一种含水铝硅酸盐矿物,长石的主要成分是铝硅酸盐,石英的主要成分为二氧化硅,②错误。水泥、沙子和水的混合物叫水泥沙浆,是建筑用黏合剂,③正确。在水泥沙浆中添加适量的水玻璃可以提高水泥沙浆的黏结性和胶凝性,④正确。]
2.制备陶瓷和水泥共同的原料是( ) 【导学号:72572155】 A.石灰石 C.石英
B.黏土 D.石膏
B [陶瓷制品的原料是黏土、长石、石英,水泥则是以石灰石、黏土、石膏
为主要原料。]
3.有关涂料的描述中,错误的是( ) A.涂料有天然涂料和合成涂料两大类
B.早期喷漆中可挥发有机溶剂含量高达95%,易污染环境 C.聚醋酸乙烯酯乳胶漆是通过缩聚反应制备的
D.涂料中的溶剂是有机溶剂(如二甲苯、甲苯、醋酸丁酯等)或水,其作用是使基料溶解或分散成为黏稠的液体,以便施工
C [聚醋酸乙烯酯的结构简式为
,它是由醋酸乙烯(醇)酯
通过加聚反应生成的,C项描述错误。A、B、D三项描述均正确。]
4.下列关于材料的说法中,正确的是( ) 【导学号:72572156】
A.二氧化硅的提纯与应用,促进了半导体元件与集成芯片的发展 B.水泥、玻璃、塑料都是高分子材料 C.钢化玻璃与普通玻璃的主要成分不同
D.通常情况下,铝合金在空气中不易被腐蚀,可用作建筑材料
D [硅的提纯与应用,促进了半导体元件与集成芯片的发展,A错误。水泥、玻璃不是高分子材料,塑料是高分子材料,B错误。钢化玻璃与普通玻璃的主要成分相同,C错误。通常情况下,铝合金在空气中不易被腐蚀,可用作建筑材料,D正确。]
5.有关起居室装修材料的选择,下列说法正确的是( ) A.起居室地面装修以铺瓷砖或天然大理石板或石膏板为宜
B.塑钢是以聚氯乙烯为基材,以碳酸钙为填充料,用玻璃纤维增强制成的 C.起居室的吊顶用材可选用玻璃板等 D.起居室装修只用大量的涂料和玻璃
B [起居室地面装修以铺瓷砖或天然大理石板为宜,不能铺石膏板,A错;起居室的吊顶用材可选用石膏板,C错;起居室装修除了用到大量的涂料和玻璃,还用到瓷砖或天然大理石板、塑钢等,D错。]
6.室内环境污染可分为化学污染、物理污染、生物污染和放射性污染,关于室内环境污染的说法不正确的是( )
【导学号:72572157】
A.化学污染主要来自装修材料挥发的有毒有机物 B.为防止生物污染应定期为居室杀菌、消毒
C.放射性污染物氡无色无味很难被人察觉,应选专业机构测量 D.为了防止室内污染应紧闭门窗 【答案】 D
7.在入住装修过的新房之前,下列做法中正确的是( ) A.紧闭门窗,防止装修面干裂、变质 B.适度开窗通气,充分地进行内外空气对流 C.用高浓度的甲醛溶液对室内环境消毒 D.在各个房间内喷洒空气清新剂,以免有异味
B [紧闭门窗不利于排出有害物质,A项错误;甲醛有毒不适用于室内环境消毒,C项错误;喷洒空气清新剂并未消除污染,D项错误。]
8.下列关于选择家居装修材料的说法错误的是( )
【导学号:72572158】
A.厨房和卫生间的地面应选用防滑瓷砖 B.家庭墙面装饰应选用水溶性乳胶漆 C.卧室应选用复合木地板 D.黏合剂应选用天然黏合剂
C [复合木地板能够释放甲醛,不宜在卧室使用。] [能力提升练]
9.某科研小组用高岭土(主要成分是Al2O3·2SiO2·2H2O并含有少量CaO和Fe2O3)研制新型净水剂(铝的化合物)。其实验步骤如下:将土样和纯碱混匀,加热熔融,冷却后用水溶解熔块、过滤、弃去残渣,滤液用盐酸酸化、过滤,分别得到沉淀和溶液,溶液即为净水剂。
(1)写出熔融时,土样的主要成分与纯碱反应的方程式(只写出一个即可): ______________________________________________________________。 (2)最后的沉淀物是________;并写出有关离子方程式:
______________________________________________________________。 (3)实验中常用的坩埚有瓷坩埚和铁坩埚,本实验在熔融土样时选用________坩埚。
【解析】 由制普通玻璃的反应原理可写出Na2CO3与SiO2的反应方程式。熔块溶解过滤的滤液中主要含有Na2SiO3、Na[Al(OH)4],加盐酸后Na2SiO3跟盐酸生成H2SiO3沉淀,Na[Al(OH)4]跟过量盐酸反应生成AlCl3做净水剂。瓷坩埚中含有SiO2,在高温下能跟Na2CO3发生反应,因此应用铁坩埚。
高温
【答案】 (1)Na2CO3+SiO2=====Na2SiO3+CO2↑
(2)H2SiO3 2H++SiO23-===H2SiO3↓ (3)铁
10.某化学兴趣小组查阅资料得知:甲醛是一种无色有刺激性气味的气体,沸点为-19.5 ℃,易溶于水,易被高锰酸钾氧化生成其他气体。甲醛对人的皮肤和呼吸器官有强烈的刺激作用。大多数装修材料中含有甲醛。请回答下列问题:
【导学号:72572159】
(1)CO使人中毒是因为很容易和人体血液中的________结合。
(2)该兴趣小组收集V1 L含有甲醛和CO的某居室空气,用如图装置测定其中甲醛和CO的含量。则装置A中盛放的试剂是________,实验中还需要测定的数据是________。为了获得较准确的实验结论,他们需要采取的方法是________(填序号)。
a.仔细做好每步操作,只做一次实验 b.在A、B间加一个干燥装置 c.重复做2~3次上述实验
【解析】 (1)CO容易和人体血液中的血红蛋白结合而使血红蛋白失去运输O2的能力,使人中毒。
(2)根据实验装置图及甲醛易溶于水而CO难溶于水可知先将甲醛和CO的混合气体通入水中,甲醛被吸收,而CO可以把装置B中的水压入到量筒中,量筒中水的体积即为CO的体积。从而确定混合气体中甲醛和CO的含量。该实验没必要增加干燥装置,为使结果可靠,应重复实验2~3次。
【答案】 (1)血红蛋白 (2)水 C中水的体积 c
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