第一篇:【人教版】高中化學(xué)選修一教案全套
從實(shí)驗(yàn)學(xué)化學(xué)
第一節(jié)化學(xué)實(shí)驗(yàn)基本方法
引言
實(shí)驗(yàn)復(fù)習(xí)首先是要對(duì)教材中的每個(gè)基本實(shí)驗(yàn),理解原理,掌握方法及注意等項(xiàng)。對(duì)實(shí)驗(yàn)中經(jīng)常碰到的常用裝置或操作進(jìn)行歸納和適當(dāng)延伸。如探究怎樣使驗(yàn)證實(shí)驗(yàn)更加操作簡(jiǎn)單,時(shí)間短、污染少;在規(guī)范的基礎(chǔ)上靈活應(yīng)用。第二是要注重教材實(shí)驗(yàn)的開(kāi)發(fā)與整合,以提高創(chuàng)新實(shí)驗(yàn)的設(shè)計(jì)能力和評(píng)價(jià)能力。如失敗原因探討與診斷,引導(dǎo)觀察分析“異常”,或結(jié)合信息材料,概括實(shí)驗(yàn)?zāi)康臍w納實(shí)驗(yàn)結(jié)論。總之要學(xué)會(huì)分析,注重表達(dá)。專題一 常見(jiàn)儀器的使用及實(shí)驗(yàn)安全 知識(shí)點(diǎn)
《高考考試大綱》
對(duì)應(yīng)教科書(shū)內(nèi)容 常用儀器的用途和使用方法 了解化學(xué)實(shí)驗(yàn)常見(jiàn)儀器的主要用途和使用方法
化學(xué)1 第一章 第一節(jié) 安全標(biāo)識(shí)、安全措施意外事故的緊急處理方法 能識(shí)別化學(xué)品安全使用標(biāo)識(shí),了解實(shí)驗(yàn)室
一般事故的預(yù)防和處理方法 化學(xué)1 第一章 第一節(jié)
一、重點(diǎn)知識(shí)解析
1.常用儀器的用途和使用方法
【用于加熱的儀器】
(1)可直接加熱的儀器:試管、蒸發(fā)皿、坩堝、燃燒匙,硬質(zhì)玻璃管。特點(diǎn):受熱面積小、材質(zhì)易均勻分散熱量。
(2)墊石棉網(wǎng)加熱的儀器:燒杯、燒瓶(圓底平底及蒸餾燒瓶)、錐形瓶等。特點(diǎn):受熱面積大,不均勻分散熱量。【計(jì)量?jī)x器】
(1)托盤(pán)天平:用于稱量物質(zhì)的質(zhì)量。精度0.1 g。稱量前調(diào)“0”點(diǎn),稱量時(shí)左物右碼,砝碼用鑷子夾取,稱量干燥的固體應(yīng)放在兩盤(pán)等質(zhì)量的紙上,易潮解或具有腐蝕性的藥品應(yīng)放在玻璃器皿中稱量。
(2)量筒:用于粗略量取一定體積的液體。精度0.1 mL。無(wú)“0”刻度。不能在量筒內(nèi)配制或進(jìn)行化學(xué)反應(yīng),量液體時(shí)量筒必須平放,觀察刻度時(shí)眼睛平視。
(3)容量瓶:用于配制一定體積,一定物質(zhì)的量濃度的溶液。用前首先檢查瓶塞是否漏液,往容量瓶轉(zhuǎn)移液體應(yīng)用玻璃棒引流,液體應(yīng)冷卻到20℃,不能在容量瓶中溶解溶質(zhì)。(4)滴定管:用于做酸、堿中和滴定。精度為0.1 mL。刻度由上向下一般為0~25 mL,但容積大于25 mL。酸式、堿式滴定管不能混用,堿式滴定管不能裝氧化性試劑,用前應(yīng)先檢查活塞處是否漏液。
(5)溫度計(jì):用于測(cè)量溫度。水銀球不能觸及反應(yīng)器壁,不能當(dāng)攪拌器使用,注意溫度計(jì)的量程。
【分離儀器】
(1)普通漏斗:用于轉(zhuǎn)移液體或分離固體液體混合物,也常用于防倒吸裝置。
(2)長(zhǎng)頸漏斗:主要用于裝配制氣反應(yīng)發(fā)生器。使用時(shí),長(zhǎng)管末端插入反應(yīng)液面以下。(3)分液漏斗:用于分離密度不同且互不相溶的液體。也常用作反應(yīng)器的隨時(shí)加液裝置。使用前應(yīng)檢驗(yàn)是否漏液,分液時(shí)下層液體由下口放出,上層液體由上口倒出。(4)干燥管:用于干燥或吸收某些氣體,氣流由大口進(jìn)小口出。(5)洗氣瓶:用于干燥氣體,或不純氣體的除雜。也可用作測(cè)氣裝置、儲(chǔ)氣裝置等。注意氣體的進(jìn)入方向,除雜:“長(zhǎng)進(jìn)短出”,排水儲(chǔ)氣:“短進(jìn)長(zhǎng)出”。2.化學(xué)實(shí)驗(yàn)安全常識(shí)
第二篇:咬文嚼字 教案人教選修
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3.4 咬文嚼字 教案(人教選修—語(yǔ)言文字應(yīng)用)
教學(xué)目標(biāo)
1、通過(guò)對(duì)文中有關(guān)幾個(gè)實(shí)例的嘗試品味,體會(huì)斟酌文字與精微準(zhǔn)確地傳情達(dá)意之間的重要關(guān)系,從而自覺(jué)養(yǎng)成“一字不肯放松”的正確謹(jǐn)嚴(yán)的語(yǔ)文學(xué)習(xí)習(xí)慣。
2、引導(dǎo)學(xué)生注意對(duì)本文語(yǔ)言的質(zhì)疑分析,培養(yǎng)求實(shí)創(chuàng)新精神。
教學(xué)過(guò)程
一、導(dǎo)入:
打一謎語(yǔ)讓同學(xué)們猜:小老鼠看書(shū)--咬文嚼字
小老鼠學(xué)習(xí)的精神應(yīng)該推廣:把書(shū)吃掉,消化掉,成為一個(gè)很有品位的小老鼠。
二、解題
“咬文嚼字”一般解釋為:過(guò)分地斟酌字詞(死摳字眼,不領(lǐng)會(huì)精神實(shí)質(zhì))。作者賦予這個(gè)成語(yǔ)一種新的意義,就是在文字運(yùn)用上“必須有一字不肯放松的謹(jǐn)嚴(yán)”。
作者提倡“咬文嚼字”,認(rèn)為語(yǔ)言文字與思想感情有密切關(guān)系,文字的優(yōu)劣要從它所表達(dá)的思想感情和表現(xiàn)的意境上去辨別,文字的運(yùn)用,要從思想感情的透徹、凝練、創(chuàng)新入手。
三、作者介紹
朱光潛(1897-1986),著名美學(xué)家、文藝?yán)碚摷摇⒎g家。筆名孟實(shí),安徽省桐城縣人。我國(guó)現(xiàn)代美學(xué)的開(kāi)拓者和奠基者之一。他學(xué)貫中西,博古通今。《西方美學(xué)史》是朱光潛最重要的一部著作,也是我國(guó)學(xué)者撰寫(xiě)的第一部美學(xué)史著作,具有開(kāi)創(chuàng)性的學(xué)術(shù)價(jià)值,代表了中國(guó)研究西方美學(xué)思想的水平。朱光潛信奉“三此主義”,即此身,此時(shí),此地。“此身應(yīng)該做而且能夠做的事,就得由此身?yè)?dān)當(dāng)起,不推諉給旁人。”“此時(shí)應(yīng)該做而且能夠做的事,就得在此時(shí)做,不拖延到未來(lái)。”“此地(我的地位、我的環(huán)境)應(yīng)該做而且能夠做的事,就得在此地做,不推諉到想象中另一地位去做。”這是朱光潛不尚空談、著眼現(xiàn)在、腳踏實(shí)地的治學(xué)精神的體現(xiàn)。他的座右銘:“以出世的精神,做入世的事業(yè)”。
主要代表作有:《文藝心理學(xué)》《談美書(shū)簡(jiǎn)》《給青年的十二封信》
四、課文分析
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《咬文嚼字》全文8段,1—7段是文章的主體,為第一部分。8段表明文章的主旨,是文章的第二部分。
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原文:紅杏枝頭春意濃
改文:紅杏枝頭春意鬧
解說(shuō):非一“鬧”字,不能形容其杏之紅,其紅之濃。“鬧”將無(wú)“聲”的景象隨著上有“聲”的意味。日常經(jīng)驗(yàn)里的視覺(jué)、聽(tīng)覺(jué)等感覺(jué)被彼此打通,多層次地將審美的精微感受傳達(dá)出來(lái)。
最后在總結(jié)課內(nèi)外諸多實(shí)例的基礎(chǔ)上讓學(xué)生明確文字和思想感情有密切關(guān)系,語(yǔ)言跟思想情感走,更動(dòng)了文字就同時(shí)更動(dòng)了思想情感。只有刻苦自勵(lì),推陳翻新,時(shí)時(shí)求思想情感和語(yǔ)言的精練與吻合,才會(huì)逐漸達(dá)到藝術(shù)的完美。
觀點(diǎn)性語(yǔ)段在最后一段,作者主要的觀點(diǎn)是:
1、應(yīng)該有謹(jǐn)嚴(yán)精神;
2、只有咬文嚼字,不斷推陳翻新,追求思想感情和語(yǔ)言的精練與吻合,才可能達(dá)到藝術(shù)的完美。
補(bǔ)充資料:
題李凝幽居 唐?賈島
閑居少鄰并,草徑入荒園。鳥(niǎo)宿池邊樹(shù),僧敲月下門(mén)。
過(guò)橋分野色,移石動(dòng)云根。暫去還來(lái)此,幽期不負(fù)言。
注解:幽居:指隱居處.云根:古人認(rèn)為云生在山石上,石為云根.幽期:歸隱所約的日期.譯文:幽閑地住在這里,很少有鄰居往來(lái),只有一條雜草遮掩的小路通向荒蕪的小園.鳥(niǎo)兒歇宿在池邊的樹(shù)上,歸來(lái)的僧人正在月下敲響山門(mén).走過(guò)小橋呈現(xiàn)出原野迷人的景色,云腳正在飄動(dòng),好像山石在移動(dòng).我暫時(shí)要離開(kāi)這里,但不久還要回來(lái),要按照約定的日期與朋友一起隱居,決不食言.錦 瑟 唐?李商隱
錦瑟無(wú)端五十弦,一弦一柱思華年。莊生曉夢(mèng)迷蝴蝶,望帝春心托杜鵑。
滄海月明珠有淚,藍(lán)田日暖玉生煙。此情可待成追憶,只是當(dāng)時(shí)已惘然。
譯文:錦瑟呀,你為何竟然有五十條弦?每弦每節(jié),都令人懷思黃金華年。我心象莊子,為蝴蝶曉夢(mèng)而迷惘; 又象望帝化杜鵑,寄托春心哀怨 滄海明月高照,鮫人泣淚皆成珠藍(lán)田紅日和暖,可看到良玉生煙。
悲歡離合之情,豈待今日來(lái)追憶,只是當(dāng)年卻漫不經(jīng)心,早已惘然。
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青玉案 宋?賀鑄
凌波不過(guò)橫塘塘路,但目送,芳?jí)m去。——眼看此女走近又離去。
錦瑟華年誰(shuí)與度?——猜想她住什么地方?有夫否?
月臺(tái)花榭,瑣窗朱戶,只有春知處——或許是那女子氣質(zhì)高雅,使人想他應(yīng)住在這種“月臺(tái)
花榭,瑣窗朱戶”的華屋吧。
碧云冉冉衡皋暮,彩筆新題斷腸句——從清晨等到日暮,佳人不再來(lái),寫(xiě)了斷腸句。
試問(wèn)閑愁都幾許?——心全亂了,愁緒滿懷。
一川煙草,滿城風(fēng)絮,梅子黃時(shí)雨!——喻情于景,愁如一川煙草,偏此時(shí)又下起梅雨,滿
城飄起柳絮,春天的雨有時(shí)確實(shí)使人惱啊。
賀鑄一生所識(shí)女子頗多,為何只對(duì)此女有這種情思,有兩個(gè)原因:一是這位女子與作者已亡故的妻有些相像,產(chǎn)生“移情”心理;二是這位女子與作者心目中的女性偶像十分貼近,使用權(quán)他一見(jiàn)而鐘情。
宋?蘇軾
獨(dú)攜天上小團(tuán)月,來(lái)試人間第二泉。
小團(tuán)月是一種名品茶(在當(dāng)時(shí)是貢茶)第二泉指的是二泉亭品二泉水和眺望太湖
例子:
紅杏枝頭春意“濃”
紅杏枝頭春意“鬧”
宋祁 《玉樓春》
東城漸覺(jué)風(fēng)光好,彀皺波紋迎客棹。綠楊煙外曉寒輕,紅杏枝頭春意鬧。
浮生長(zhǎng)恨歡娛少,肯愛(ài)千金輕一笑?
縠皺:即皺紗,喻水的波紋。
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浮生:指飄浮無(wú)定的短暫人生
劉公勇在詞話里稱“一鬧字卓絕千古”。“鬧”字好就好在準(zhǔn)確、鮮明、生動(dòng),帶有動(dòng)態(tài)地刻畫(huà)春天的蓬勃生機(jī),并把作者對(duì)春天這樣一個(gè)萬(wàn)物萌發(fā),生機(jī)盎然的季節(jié)的到來(lái)的欣喜用一個(gè)“鬧”字表達(dá)了出來(lái)。作者的感情態(tài)度盡含于一個(gè)鬧字之中。
課堂小練習(xí):
在詩(shī)中的括號(hào)內(nèi),填入六個(gè)字,構(gòu)成六幅畫(huà)。塞鴻秋·潯陽(yáng)即景 元·周德清
長(zhǎng)江萬(wàn)里白如(),淮山數(shù)點(diǎn)青如(),江帆幾片疾如(),山泉千尺飛如()。晚云都變露,新月初學(xué)(),塞鴻一字來(lái)如()。
原詩(shī)
塞鴻秋·潯陽(yáng)即景 周德清
長(zhǎng)江萬(wàn)里白如練,淮山數(shù)點(diǎn)青如淀,江帆幾片疾如箭,山泉千尺飛如電。
晚霞都變露,新月初學(xué)扇,塞鴻一字來(lái)如線。
(四)閱讀下列文字,說(shuō)說(shuō)修改稿好在哪里?
原稿:
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老漁民長(zhǎng)得高大結(jié)實(shí),看樣子60歲左右,嘴巴下留著一把花白胡子。瞧他那眉目神氣,就像秋天的晴空一樣,晴朗又透明又深沉。
修改稿:
老漁民長(zhǎng)得高大結(jié)實(shí),留著一把花白胡子。瞧他那眉目神氣,就像秋天的高空一樣,又晴朗又深沉。
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第三篇:人教新課標(biāo)必修一 Unit1 Friendship[全套教案]
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Unit 1 Friendship Teaching goals:
*語(yǔ)言知識(shí)
1.to talk about friends and friendship, and interpersonal relationship 2.to practise expressing attitudes, agreement and disagreement, and certainty 3.to master some sentences about giving advice 4.to learn to use the Direct Speech and Indirect Speech(1): statements and questions 5.to learn about communication skills
*語(yǔ)言技能和學(xué)習(xí)策略
1.to develop listening skills by doing exercises in listening task 2.to develop speaking skills by finishing the speaking task and other activities like discussion and oral practice 3.to develop reading skills through the reading materials in this unit 4.to learn to write a letter of advice
*文化意識(shí)
1.to know about friend and the real meaning of friend 2.to learn how to get along with others
*情感態(tài)度
1.to arouse the interest in learning English 2.to learn to express their feeling of friends and friendship
Teaching key points: 1.how to improve students’ speaking and cooperating abilities
2.learn to use the Direct Speech and Indirect Speech(1):statements and questions 3.master some words and expressions Teaching difficult points: 1.train the students’ speaking, listening, reading and writing abilities 2.how to improve students’ cooperating abilities Teaching methods: Student-focus approach and task-based approach Learning methods: Cooperative study Teaching aids: Computer
The First Period(Warming up &Speaking)Teaching aims: 1.to know about different kinds of friendship 嘉興英語(yǔ)教學(xué)網(wǎng) www.tmdps.cn 收集整理
2.to learn some words of describing friend and friendship 3.to master some useful words and expressions Teaching methods: 1.discussing
2.cooperative learning
Teaching materials: Warming up Teaching procedures: Step One: Leading-in 1.Free talk: Something about friend and friendship Ask the Ss to describe one of their friends----their appearance, personality, hobbies, etc.Qs: What’s your friend like?
What does he/she like to do in his/her spare time?
What personality does he/she have? Step Two: Discussion
1.Writing the following statement on the blackboard We all agree that to have a good friend , you need to be a good friend.2.Ask the Ss: What do you think of this statement and how can you be a good friend? Let the Ss express their views 3.Have the Ss get into groups of four to list some qualities of a person they would like as a friend.Ss may list: honest, friendly, open-minded, generous, helpful, patient, good-tempered, trustworthy, careful, full of love, caring, responsible, interesting, brave, easygoing, outgoing, warm-hearted, kind, selfness, tolerant, intelligent… 4.Have a member of each group report on what their lists have and list them on the blackboard 5.Ask the class whether or not they agree with all the qualities listed Step Three: Doing the survey and explanation 1.Have the Ss do the survey in the textbook and let them work out their score.2.Teacher explain each item Question 1 deal with how thoughtful you are towards others.The scoring reflects your concern for others.So one point for A gets the lowest score because it is the most selfish response.B get the highest score because it show a concern for your friend as well as your wish to go to see a film.C gets a slightly lower score because although it shows you want to go with your friend(because you change the plan), you do not help your friend.Question 2 is concerned with fairness.A gets the lowest score because you are not giving your friend another chance to behave better this time.B gets a higher score because you let your friend borrow the camera again.This shows kindness and forgiveness or the trouble you had when it was returned broken.But you are not balancing his heeds against your own.That is why C gets the highest score.You are showing your friend that you will trust him/her with the camera again but this time you are giving him / her rules in case it gets broken.嘉興英語(yǔ)教學(xué)網(wǎng) www.tmdps.cn 收集整理
Question 3 deals with your concern for others.A get the lowest score because you would put anything else that needed to be done aside and concentrate only on your friend.This is not responsible.You have things that you need to do.Of course your friend is important but not more important than you responsibilities.B gets a higher score because it shows some concern for your friend and some understanding that you have important things to do too.But it does not show any real interest in his / her problem.C get the highest score because it not only shows concern for your friend but a recognition that you have responsibilities too.Question 4 is concerned with responsibilities to a friend.A provides the correct amount of responsibility to your friend.You recognize that it was your fault and will put it right and pay for the damage.So it gets the highest score.B provides some understanding that you are responsible.You put the situation right but you do not pay for the damage yourself.So it does not get the highest score.C gets the lowest score because you expect your friend to pay for your mistakes even though you were doing your friend a favour.Question 5 is concerned with honesty.If you let your friend look at your paper or somebody else’s paper, you are helping them to cheat.That is not honest, so answers A and C get no marks.But it takes courage to tell your friend that they should have studied and that they cannot look at your paper.That is also the honest answer.So you get 6 points for B, which is more than any other in the quiz.Step Four: Language points Teacher explain language points with some slides 1.add v.1)to put together with something else so as to increase the number, size, importance, etc.增加,添加
eg.Please add something to what I’ve said, John.2)to join numbers, amount, etc so as to find the total eg.Add up these figure for me, please.常用結(jié)構(gòu):
add up / together sth.把…加起來(lái),合計(jì) add sth.to sth.把…加到/進(jìn) add to(=increase)增加了… add up to 合計(jì),共計(jì) add in 包括…,算進(jìn)
2.pay to get it repaired
花錢(qián)讓人去修理
3.upset
adj.worred;annoyed 不安的;使心煩意亂的
v.cause to worry, to be sad, to be angry, not to be calm, etc.使不安;使心煩意亂
eg.He was upset when he heard the news.His cheating in the exam upset his teacher.4.ignore vt.to pay no attention to sth.忽視;對(duì)…不予理睬 eg.Ignore the child if he misbehaves and he’ll stop soon.ignorant adj.無(wú)知的;不知的 ignorance n.無(wú)知;愚昧 嘉興英語(yǔ)教學(xué)網(wǎng) www.tmdps.cn 收集整理
5.calm
vt.to make sth./ sb.become quiet 使鎮(zhèn)靜;使平靜
adj.not excited, nervous or upset 鎮(zhèn)靜的;沉著的
calm down 鎮(zhèn)靜;平靜
calm down sb.=calm sb.Down
使某人鎮(zhèn)靜 sb.calm down(vi.)
某人平靜下來(lái) eg.The excited girl quickly calmed down.He took a few deep breaths to calm himself down.6.have got to do sth.(口語(yǔ))=have to do sth.不得不做某事;必須做某事
eg.Since you’re no longer a child now, you have got to make money to support the family.*have got to在變疑問(wèn)句或否定句時(shí),不再另加助動(dòng)詞,而have to則須加助動(dòng)詞do.have got to前不用情態(tài)動(dòng)詞,而have to前則可以。如: eg.Have you got to writ an assignment for your teacher? 7.be concerned about / for : be worried about eg.We’re all concerned about her safety.8.cheat
vt.1)to act in a dishonest way in order to win
欺騙;作弊
eg.Any student caught cheating will have to leave the classroom.2)to take from(someone)in a dishonest way 騙;騙取
eg.They cheated the old woman(out)of her money by making her sign a document she didn’t understand.n.1)an act of cheating
作弊行為
2)one who cheats
騙子
Step Five: Speaking 1.Get the Ss to work in groups of 4.2.Ask the Ss to use the questionnaire in Warming up as an example and discuss about designing questions.3.Follow the steps in this part and start the discussion like this: A: Now let us design a questionnaire to find out what kind of friend one is.B: OK.First we must think of four questions and three possible answers to each question.C: What about the first question? Have you got one in mind? D: Suppose your friend has taken away your book by mistake.What will you do or say to him / her? …
4.Teacher go around in the classroom and check their discussion.Step Six: Assignments 1.Ask Ss to consider the following question;What is / are the most important quality / qualities that a friend needs to have? 2.Prepare for Reading
嘉興英語(yǔ)教學(xué)網(wǎng) www.tmdps.cn 收集整理
The Second and Third Period
(reading and language points)Teaching aims:
1.to know about the story of Anne’s Diary
2.to promote the Ss’ abilities of reading comprehension 3.to learn about the following words and expressions: readon;list;go through;hide away;set down;a series of;outdoors;crazy;spellbound;on purpose;dare;happen to do sth.;It’s the first time that… Teaching methods: 1.reading and discussion 2.cooperative learning and speaking Teaching materials: Reading, Comprehending Teaching procedures: Step One: Leading-in Ask their opinions on the question mentioned in the assignment of last period.Step Two: Pre-reading Let the Ss think about the questions in Pre-reading, and express their own views to the whole class.Step Three: Reading
1.Ask the Ss to look at the pictures and the heading, guess what the text might be about.2.Get the Ss to skim the passage and answer the following questions: What’s Anne’s best friend?
What does her diary mainly talk about?(1.Anne’s best friend is her diary.2.It’s about Anne’s feeling of hiding away.She especially missed going outside and enjoying nature.3.Let the Ss read the passage and discuss the following questions: 1)Imagine what it might be like if they had to stay in their bedroom for a whole year.You could not leave it even to go to the WC or get a cup of tea.How would they feel? 2)If you are only allowed to have five things with you in the hiding place because there is very little room, what would you choose? 3)Try to guess why the windows had to stay closed.4)Guess the meanings of the word “crazy” and “spellbound” according to the context.Step Four: Discussing the style Ask the Ss: 1.What do you think is the purpose of this passage? Why did Anne write it? 2.Do you think it is successful? Do you understand Anne’s feelings?
3.What is Anne’s tone? In other words, is the author angry, sad, happy or thrilled? 4.What is Anne’s point of view? Do you agree with it? If so, why? If not, why not? Step Five: Listen to the text and comprehend it Step Six: Language points 1.go through 嘉興英語(yǔ)教學(xué)網(wǎng) www.tmdps.cn 收集整理
1)to examine carefully
仔細(xì)閱讀或研究 eg.I went through the students’ papers last night.2)to experience 經(jīng)歷;遭受或忍受
eg.You really don’t know what we went through while working on this project.2.hide away 3)vi.to go somewhere where you hope you will not be seen or found 躲避;隱匿
hide away +地點(diǎn)
eg.The thief hid away in a friends’ house for several weeks after the robbery.4)to put or keep sth./sb.in a place where they / it can’t be seen or found 藏;隱蔽
hide away sth./ hide sth.away eg.Why do you hide your thoughts away from me? 3.set down 5)write down 寫(xiě)下;記下
eg.I’ll set down the story as it was told to me.6)put down 放下;擱下 set down sth./set sth.down eg.He set down a basket on the ground.4.series
n.(單復(fù)數(shù)同形)
a series of 一連串的;一系列的 5.crazy
adj.7)mad, foolish 瘋狂的;愚蠢的
It is crazy of sb.to do sth.= sb be crazy to do sth.eg.It’s crazy to go out in such hot weather.8)wildly excited;very interested 狂熱的;著迷的 grow / be crazy about sb./ sth.eg.The boys are crazy about the girl singer.9)like crazy 發(fā)瘋似的;拼命地
eg.He talked like crazy;I couldn’t understand what he said.6.I wonder if it’s because I haven’tt been able to be outdoors for so long that ….*I wonder if / whether…
eg.I wonder if you can help me? *It’s because …
it is 后的表原因的從句中,只能用because來(lái)引導(dǎo),不能用since或as.eg.Why did you go to school on foot?
It is because my bike had broken.7.spellbind
v.to hold the complete attention of 吸引人,迷人;使入迷
eg.The children watched spellbound as the magician took rabbits from his hat.9.stay
v.to continue to be in a particular state or situatioin 系動(dòng)詞,表是狀態(tài)。后跟名詞或形容詞,不能用于被動(dòng)語(yǔ)態(tài)和進(jìn)行時(shí)態(tài)。eg.He stayed single all his life.10.on purpose 嘉興英語(yǔ)教學(xué)網(wǎng) www.tmdps.cn 收集整理
1)故意地(反義:by chance / accident)
eg.I think she lost the key on purpose.2)on purpose to do sth.為了要…而特地
eg.He went to town on purpose to sell one of his paintings.10.far
adv.“過(guò)于;…得多” ,表示程度,經(jīng)常與too或形容詞、副詞的比較級(jí)連用。
eg.She speaks English far better than I.This room is far too warm.cf.very, much, far 11.dare 1)modal.v.多用于否定句、疑問(wèn)句、條件狀語(yǔ)從句、whether(if)等名詞性從句或有否定意義的句中,后接動(dòng)詞原形。沒(méi)有人稱和數(shù)的變化,其時(shí)態(tài)只有現(xiàn)在時(shí)和過(guò)去時(shí)。否定式在其后加not.eg.How dare he say such a word!
If you dare do that again, you’ll be punished.2)vt.敢,膽敢。有人稱、數(shù)和時(shí)態(tài)的變化。在否定句和疑問(wèn)句中,dare后的to可保留也可省略。
eg.I wonder how he dare to day such words.12.happen to do sth.It so(just)happened that… 不能用于進(jìn)行時(shí)態(tài)。
eg.I happened to be out when he came.= It so happened that I was out when he came.13.It’s the first time that…
eg.It is the first time that I have seen the sea.Step Seven: Comprehending Get the Ss to do the exercises in this part.Step Eight: Consolidation Listen to the text again to appreciate it.Step Nine: Assignments 1.Read the key sentences in the text 2.do the exercises on Wb(Page 41-42)
The Fourth Period(Listening)Teaching aims: to train and develop listening skills by listening to the listening exercises in this unit Teaching methods: Listening and speaking Teaching materials: listening parts on Page 6 and Page 41 and Page 43 Teaching procedures: Step One: Revision Check the answers to the homework Step Two: Listening 1.Listen to the exercises on Page 6 嘉興英語(yǔ)教學(xué)網(wǎng) www.tmdps.cn 收集整理
2.Guess the words by listening to the tape and write them down Step Three: Listening to the passage Fill in the blanks on Page 41 Step Four: Speaking
Listen to the tape and discuss questions in groups of four, express your own views.Step Five: Listening task 1.Discuss with the Ss whether they always do what their parents tell them.2.Have the Ss listen to the passage.3.Fill in the table
4.Work in pairs to give some advice to Anne Step Six: Assignments 1.Do the exercises on Page 42(Ex 1,2)2.Revise the Object Clause
The Fifth Period(Discovering Useful Structures)Teaching aims: Let the Ss use the Direct Speech and Indirect Speech Teaching methods: 1.discovery learning 2.cooperative learning Teaching materials: Page 5 Teaching procedures: Step One: Revision 1.Check the homework with the Ss 2.Revise the Object clause
Exercise: Rewrite the following sentences.1.I go to school by bike.(He said…)
2.Will you forget to do your homework?(Mary asked him…)3.When did you come here?(They asked me…)4.What has he said?(Do you know…)
5.Anne is watching TV now.(Mother told me …)Step Two: discovering useful structures 1.Present some sentences for Ss
1)My friend says, “ I will come here tomorrow?”
如果此時(shí)此地,你來(lái)轉(zhuǎn)述,應(yīng)該說(shuō):
My friend says she / he will come here tomorrow? 如果時(shí)間變了,地點(diǎn)不變,你來(lái)轉(zhuǎn)述,應(yīng)該說(shuō): My friend said she / he would come here the next day.如果地點(diǎn)變了,時(shí)間還是今天,你來(lái)轉(zhuǎn)述,應(yīng)該說(shuō): My friend sayd she / he will go there tomorrow.如果時(shí)間地點(diǎn)都變了,你來(lái)轉(zhuǎn)述,應(yīng)該說(shuō): My friend said She / he would go there the next day.嘉興英語(yǔ)教學(xué)網(wǎng) www.tmdps.cn 收集整理
如果由別人轉(zhuǎn)述,時(shí)間地點(diǎn)都變了,應(yīng)該說(shuō):
He/ She said he /she would go there the next day.*使用直接引語(yǔ)和間接引語(yǔ)要注意具體語(yǔ)境。
2)“Do you go to the park yesterday?” He asked me.He asked me if / whether I went to the park the day before.3)Kate said to John, “What’s your favourite food?”
Kate asked John what his favourite food was.2.Get the Ss to have a look at Part 1 in “Discovering useful structures” and sum up this grammar point.人稱、時(shí)態(tài)、指示代詞、時(shí)間狀語(yǔ)、地點(diǎn)狀語(yǔ)等的變化。Step Three: Practice 1.Do the first tow sentences in Part 2 as examples.2.Check the answers together.Step Four: Assignments 1.Wb, Page 42, 43(Individual, Groups)2.Prepare for Reading on Page 44
The Sixth Period(Reading)Teaching aims:
1.to learn about friendship in Hawaii 2.to promote the Ss’ abilities of reading comprehension 3.to learn about the following words and expressions: way;the second important;It’s believed that…;in peace;those who …;etc.Teaching methods: 1.reading and discussion
2.cooperative learning and speaking Teaching methods: Reading(Page 44)Teaching procedures: Step One: Leading-in
1.Ask the Ss if they can think of any place in the world where Chinese and Western cultures live side by side.(Hong Kong, Macao, Singapore, the Philippines, San Francisco, etc.)Step Two: Reading 1.Get the Ss to read the passage and try to finish the table in Ex1.2.Read the passage carefully again and discuss the questions in Ex2.3.Report their discussion Step Three: Listening to the text and comprehend it Step Four: Language points 1.the way to do sth./ the way of doing sth.2.the second most important the second + adj.(最高級(jí))the third + adj.(最高級(jí))
eg.The Yellow River is the second longest river in China.嘉興英語(yǔ)教學(xué)網(wǎng) www.tmdps.cn 收集整理
China is the third largest country in the world.3.to enjoy the land = in order to enjoy the land eg.To make the w8th Olympic Games the game ever, Beijing will make several changes.* to do和 in order to do可以置于句首、句末,而 so as to do只能置于句末。4.Indeed, Hawaii is a place where ….small communities.5.It’s believed that the islands can be a paradise ….It’s believed that …= People believe that …
eg.It’s believed that they arrived more than 30,000 years ago.6.in peace 7.… they are really talking about all those who live on the islands.those who…=people who … “凡…的人”
eg.The teacher praised those who had done good deeds.We find it our duty to help those who are in trouble.8.Living in peace, Hawaiians has developed …
現(xiàn)在分詞短語(yǔ)作原因狀語(yǔ),相當(dāng)于 As they are living in peace.9.Perhaps this is how most visitors will remember their new friendship.Step Five: Listening to the text and enjoy it
The Seventh Period(Speaking Task and Writing)Teaching aims: 1.to develop Ss’ speaking ability and learn to express their own views 2.enable Ss to write a letter of advice Teaching methods: 1.tasked-based learning 2.speaking Teaching procedures: Step One: Speaking task Task One: Ex1(Page 45)1.Get the Ss to work in pairs, have them read the situations and choose one to discuss.2.Ask the Ss to present their dialogue.Task Two: Ex2(Page 45-46)1.Ask the Ss to look at the pictures.2.Work in groups of four and talk about whether they are doing is cool or not.3.Try to express their own views to the whole class.Step Two: Writing
Task One: Ask the Ss to write a letter of advice 1.Get the S to read the letter on Page 7 and understand it.2.Ask the Ss to work in pairs and talk about how to answer the letter.3.Write the letter in reply down.10 嘉興英語(yǔ)教學(xué)網(wǎng) www.tmdps.cn 收集整理
Task Two: Ask the Ss to write a passage about their opinions on friend and friendship 1.Read the proverbs carefully.2.Write a passage to express their own opinions.Step Three: Assignments 1.Fill in the form in Sum up(Page 8)2.Fill in the form in Checking yourself(Page 47)11
第四篇:高中物理選修3-5全套教案--動(dòng)量守恒定律(一)
16.2 動(dòng)量守恒定律
(一)★新課標(biāo)要求
(一)知識(shí)與技能
理解動(dòng)量守恒定律的確切含義和表達(dá)式,知道定律的適用條件和適用范圍
(二)過(guò)程與方法
在理解動(dòng)量守恒定律的確切含義的基礎(chǔ)上正確區(qū)分內(nèi)力和外力
(三)情感、態(tài)度與價(jià)值觀
培養(yǎng)邏輯思維能力,會(huì)應(yīng)用動(dòng)量守恒定律分析計(jì)算有關(guān)問(wèn)題 ★教學(xué)重點(diǎn)
動(dòng)量的概念和動(dòng)量守恒定律 ★教學(xué)難點(diǎn)
動(dòng)量的變化和動(dòng)量守恒的條件. ★教學(xué)方法
教師啟發(fā)、引導(dǎo),學(xué)生討論、交流。★教學(xué)用具:
投影片,多媒體輔助教學(xué)設(shè)備 ★課時(shí)安排 1 課時(shí)
★教學(xué)過(guò)程
(一)引入新課
上節(jié)課的探究使我們看到,不論哪一種形式的碰撞,碰撞前后mυ的矢量和保持不變,因此mυ很可能具有特別的物理意義。
(二)進(jìn)行新課
1.動(dòng)量(momentum)及其變化
(1)動(dòng)量的定義:物體的質(zhì)量與速度的乘積,稱為(物體的)動(dòng)量。記為p=mv.單位:kg·m/s讀作“千克米每秒”。
理解要點(diǎn):
①狀態(tài)量:動(dòng)量包含了“參與運(yùn)動(dòng)的物質(zhì)”與“運(yùn)動(dòng)速度”兩方面的信息,反映了由這兩方面共同決定的物體的運(yùn)動(dòng)狀態(tài),具有瞬時(shí)性。
師:大家知道,速度也是個(gè)狀態(tài)量,但它是個(gè)運(yùn)動(dòng)學(xué)概念,只反映運(yùn)動(dòng)的快慢和方向,而運(yùn)動(dòng),歸根結(jié)底是物質(zhì)的運(yùn)動(dòng),沒(méi)有了物質(zhì)便沒(méi)有運(yùn)動(dòng).顯然地,動(dòng)量包含了“參與運(yùn)動(dòng)的物質(zhì)”和“運(yùn)動(dòng)速度”兩方面的信息,更能從本質(zhì)上揭示物體的運(yùn)動(dòng)狀態(tài),是一個(gè)動(dòng)力學(xué)概念.②矢量性:動(dòng)量的方向與速度方向一致。師:綜上所述:我們用動(dòng)量來(lái)描述運(yùn)動(dòng)物體所能產(chǎn)生的機(jī)械效果強(qiáng)弱以及這個(gè)效果發(fā)生的方向,動(dòng)量的大小等于質(zhì)量和速度的乘積,動(dòng)量的方向與速度方向一致。
(2)動(dòng)量的變化量:
定義:若運(yùn)動(dòng)物體在某一過(guò)程的始、末動(dòng)量分別為p和p′,則稱:△p= p′-p為物體在該過(guò)程中的動(dòng)量變化。
強(qiáng)調(diào)指出:動(dòng)量變化△p是矢量。方向與速度變化量△v相同。一維情況下:Δp=mΔυ= mυ2-mΔυ
1矢量差 【例1(投影)】
一個(gè)質(zhì)量是0.1kg的鋼球,以6m/s的速度水平向右運(yùn)動(dòng),碰到一個(gè)堅(jiān)硬的障礙物后被彈回,沿著同一直線以6m/s的速度水平向左運(yùn)動(dòng),碰撞前后鋼球的動(dòng)量有沒(méi)有變化?變化了多少?
【學(xué)生討論,自己完成。老師重點(diǎn)引導(dǎo)學(xué)生分析題意,分析物理情景,規(guī)范答題過(guò)程,詳細(xì)過(guò)程見(jiàn)教材,解答略】
2.系統(tǒng)
內(nèi)力和外力
【學(xué)生閱讀討論,什么是系統(tǒng)?什么是內(nèi)力和外力?】(1)系統(tǒng):相互作用的物體組成系統(tǒng)。(2)內(nèi)力:系統(tǒng)內(nèi)物體相互間的作用力(3)外力:外物對(duì)系統(tǒng)內(nèi)物體的作用力
〖教師對(duì)上述概念給予足夠的解釋,引發(fā)學(xué)生思考和討論,加強(qiáng)理解〗 分析上節(jié)課兩球碰撞得出的結(jié)論的條件:
兩球碰撞時(shí)除了它們相互間的作用力(系統(tǒng)的內(nèi)力)外,還受到各自的重力和支持力的作用,使它們彼此平衡。氣墊導(dǎo)軌與兩滑塊間的摩擦可以不計(jì),所以說(shuō)m1和m2系統(tǒng)不受外力,或說(shuō)它們所受的合外力為零。
3.動(dòng)量守恒定律(law of conservation of momentum)
(1)內(nèi)容:一個(gè)系統(tǒng)不受外力或者所受外力的和為零,這個(gè)系統(tǒng)的總動(dòng)量保持不變。這個(gè)結(jié)論叫做動(dòng)量守恒定律。
公式:m1υ1+ m2υ2= m1υ1′+ m2υ2′(2)注意點(diǎn):
① 研究對(duì)象:幾個(gè)相互作用的物體組成的系統(tǒng)(如:碰撞)。② 矢量性:以上表達(dá)式是矢量表達(dá)式,列式前應(yīng)先規(guī)定正方向; ③ 同一性(即所用速度都是相對(duì)同一參考系、同一時(shí)刻而言的)
④ 條件:系統(tǒng)不受外力,或受合外力為0。要正確區(qū)分內(nèi)力和外力;當(dāng)F內(nèi)>>F外時(shí),系統(tǒng)動(dòng)量可視為守恒;
思考與討論: 如圖所示,子彈打進(jìn)與固定于墻壁的彈簧相連的木塊,此系統(tǒng)從子彈開(kāi)始入射木塊到彈簧壓縮到最短的過(guò)程中,子彈與木塊作為一個(gè)系統(tǒng)動(dòng)量是否守恒?說(shuō)明理由。
B A 分析:此題重在引導(dǎo)學(xué)生針對(duì)不同的對(duì)象(系統(tǒng)),對(duì)應(yīng)不同的過(guò)程中,受力情況不同,總動(dòng)量可能變化,可能守恒。
〖通過(guò)此題,讓學(xué)生明白:在學(xué)習(xí)物理的過(guò)程中,重要的一項(xiàng)基本功是正確恰當(dāng)?shù)剡x取研究對(duì)象、研究過(guò)程,根據(jù)實(shí)際情況選用對(duì)應(yīng)的物理規(guī)律,不能生搬硬套。〗
【例2(投影)】
質(zhì)量為30kg的小孩以8m/s的水平速度跳上一輛靜止在水平軌道上的平板車,已知平板車的質(zhì)量為90kg,求小孩跳上車后他們共同的速度。
解:取小孩和平板車作為系統(tǒng),由于整個(gè)系統(tǒng)所受合外為為零,所以系統(tǒng)動(dòng)量守恒。規(guī)定小孩初速度方向?yàn)檎瑒t: 相互作用前:v1=8m/s,v2=0,設(shè)小孩跳上車后他們共同的速度速度為v′,由動(dòng)量守恒定律得 m1v1=(m1+m2)v′
解得
v′=m1v1=2m/s,m1?m2數(shù)值大于零,表明速度方向與所取正方向一致。
(三)課堂小結(jié)
教師活動(dòng):讓學(xué)生概括總結(jié)本節(jié)的內(nèi)容。請(qǐng)一個(gè)同學(xué)到黑板上總結(jié),其他同學(xué)在筆記本上總結(jié),然后請(qǐng)同學(xué)評(píng)價(jià)黑板上的小結(jié)內(nèi)容。
學(xué)生活動(dòng):認(rèn)真總結(jié)概括本節(jié)內(nèi)容,并把自己這節(jié)課的體會(huì)寫(xiě)下來(lái)、比較黑板上的小結(jié)和自己的小結(jié),看誰(shuí)的更好,好在什么地方。
點(diǎn)評(píng):總結(jié)課堂內(nèi)容,培養(yǎng)學(xué)生概括總結(jié)能力。
教師要放開(kāi),讓學(xué)生自己總結(jié)所學(xué)內(nèi)容,允許內(nèi)容的順序不同,從而構(gòu)建他們自己的知識(shí)框架。
(四)作業(yè):“問(wèn)題與練習(xí)”2、3、4題 課后補(bǔ)充練習(xí)
1.一爆竹在空中的水平速度為υ,若由于爆炸分裂成兩塊,質(zhì)量分別為m1和m2,其中質(zhì)量為m1的碎塊以υ1速度向相反的方向運(yùn)動(dòng),求另一塊碎片的速度。
2.小車質(zhì)量為200kg,車上有一質(zhì)量為50kg的人。小車以5m/s的速度向東勻速行使,人以1m/s的速度向后跳離車子,求:人離開(kāi)后車的速度。(5.6m/s)
第五篇:高中化學(xué)人教必修一1.1.2-蒸餾和萃取--教案
人教必修1
教案
蒸餾和萃取1.1.2
一、教材分析:蒸餾和萃取是在實(shí)際生產(chǎn)生活中有著廣泛應(yīng)用的分離和提純技術(shù),海水淡化問(wèn)題是目前解決全球淡水日益緊缺問(wèn)題的重要途徑,這為選修《化學(xué)與技術(shù)》奠定了一定的知識(shí)基礎(chǔ)。萃取對(duì)于學(xué)生來(lái)說(shuō)是全新的分離和提純技術(shù),它是對(duì)溶解性規(guī)律的一個(gè)應(yīng)用,其原理也在今后鹵族元素和有機(jī)物的學(xué)習(xí)中多次體現(xiàn),在生活中也有多方面 的應(yīng)用。本節(jié)課教學(xué)內(nèi)容主要包括兩個(gè)方面:
(一)復(fù)習(xí)蒸餾的原理,掌握實(shí)驗(yàn)室規(guī)范的蒸餾裝置。這部分內(nèi)容只作復(fù)習(xí)和簡(jiǎn)單的擴(kuò)充;
(二)介紹萃取的原理和裝置,特別是實(shí)驗(yàn)操作中的細(xì)節(jié)。這部分知識(shí)為新知識(shí),應(yīng)采用靈活多樣的教學(xué)手段由淺入深地讓學(xué)生理解和掌握。蒸餾和萃取是高中階段的兩個(gè)基本實(shí)驗(yàn)操作,學(xué)生對(duì)于相關(guān)內(nèi)容及部分儀器還比較陌生,本節(jié)課的主要目的就是讓學(xué)生了解蒸餾和萃取的操作及過(guò)程,學(xué)習(xí)一些儀器的使用方法,并進(jìn)
一步豐富分離提純物質(zhì)的方法和手段。
二、教學(xué)目標(biāo)
(一)知識(shí)與能力 .認(rèn)識(shí)化學(xué)實(shí)驗(yàn)在學(xué)習(xí)和研究化學(xué)中的作用。1.知道液體混合物分離和提純的常用方法——蒸餾和萃取,能根據(jù)物質(zhì)的性質(zhì)設(shè)計(jì)分離和提純方案,并初步掌握2
其操作技能。體驗(yàn)科學(xué)探究的過(guò)程,通過(guò)親自實(shí)驗(yàn)和教師指導(dǎo),讓學(xué)生掌握做好實(shí)驗(yàn)的方法。
(二)過(guò)程與方法: 能發(fā)現(xiàn)生產(chǎn)、生活中有意義的化學(xué)問(wèn)題,建立化學(xué)為生產(chǎn)、生活服務(wù)的觀點(diǎn)。
(三)情感態(tài)度與價(jià)值觀:
教學(xué)重點(diǎn)、難點(diǎn)
三、蒸餾和萃取的實(shí)驗(yàn)原理以及操作過(guò)程。教學(xué)重點(diǎn):
蒸餾和萃取的掌握和應(yīng)用。教學(xué)難點(diǎn):
四、教學(xué)過(guò)程:【引言】上節(jié)課我們學(xué)習(xí)了粗鹽的提純,通過(guò)除雜質(zhì)過(guò)濾的方法得到比較純的鹽水,大家想想如果我們要把鹽水變
頁(yè)6 共 頁(yè)1 第
為淡水,該怎么做呢?比如說(shuō)在海邊,漁民們是怎么解決生活用水的問(wèn)題;前段時(shí)間,中央電視臺(tái)播放了鄭和下西洋的那段歷史,大
家知道他們是怎么解決長(zhǎng)期在海上漂泊的吃水問(wèn)題嗎?
【展示】海水變淡水【引】做湯的時(shí)候,觀察過(guò)鍋蓋嗎?鍋蓋上有水珠,這水珠與湯不什么不同?為什么會(huì)有水珠?水蒸汽凝結(jié)?為什
么水蒸汽會(huì)凝結(jié)成水珠?我們?cè)诨瘜W(xué)中應(yīng)怎么稱呼?那么這是一個(gè)什么過(guò)程,水蒸汽遇溫度低的鍋蓋而凝成水珠附于鍋蓋。湯沸騰后,【講】 大家想一想蒸餾是不是一種分離混合物的方法?如果是,那么是分離什么樣的混合物?混合物的分離和提純除了過(guò)濾、蒸發(fā)外,還有其他很多方法,這節(jié)課,我們來(lái)學(xué)習(xí)另外兩種新方法:蒸餾和【過(guò)】 萃取)二(【板書(shū)】(distillation and extraction)蒸餾和萃取 【過(guò)】首先,讓我們利用實(shí)驗(yàn)室通過(guò)蒸餾的方法除去自來(lái)水中的雜質(zhì)制取蒸餾水的實(shí)驗(yàn)來(lái)學(xué)習(xí)蒸餾的過(guò)程、蒸餾1【板書(shū)】Cl使水中含有因?yàn)樽詠?lái)水廠使用了消毒劑氯對(duì)水進(jìn)行了消毒。我們引用的自來(lái)水是純凈的水嗎?不是。【引入】―。我們可以利用加入硝酸銀溶液檢驗(yàn)是否含有氯離子。
【實(shí)驗(yàn)演示】自來(lái)水中加入硝酸酸化的硝酸銀溶液【講】有明顯白色沉淀生成,證明自來(lái)水中含有氯離子。那么,我們應(yīng)該用什么方法除去自來(lái)水中的氯離子呢?能
否向上一堂課中使用化學(xué)方法,加入試劑反應(yīng)除去?不能。加入試劑后會(huì)引入新的雜質(zhì),達(dá)不到我們實(shí)驗(yàn)?zāi)康摹R氲玫郊儍羲?梢允褂眉訜釋⑺優(yōu)樗羝?)然后再冷凝為純凈的液態(tài)蒸餾水。
【小結(jié)】實(shí)驗(yàn)室就是使用蒸餾的方法制取蒸餾水。
【投】原理:利用互溶的液體混合物中各組分的沸點(diǎn)不同,給液體混合物加熱,使其中的某一組分變成蒸氣再冷凝成(1)的水提純其Fe3+(例如蒸餾含有液體,從而達(dá)到分離提純的目的。蒸餾一般用于分離沸點(diǎn)相差較大的液體混合物。頁(yè)6 共 頁(yè)2 第
中水份,蒸餾石油提純不同沸點(diǎn)的有機(jī)組分)、錐形瓶、膠管)儀器:鐵架臺(tái)、酒精燈、石棉網(wǎng)、蒸餾燒瓶、冷凝管、溫度計(jì)、膠塞、牛角管(尾接管)2(【實(shí)驗(yàn)演示】實(shí)驗(yàn)室制取蒸餾水)蒸餾時(shí)的注意事項(xiàng):3(【投】 防止爆沸。)碎瓷片(,燒瓶要墊上石棉網(wǎng)加熱,燒瓶中還要加入沸石2/3燒瓶?jī)?nèi)液體的容積不超過(guò)a.溫度計(jì)下端水銀泡應(yīng)置于燒瓶支管處,測(cè)量逸出氣體的溫度。b.冷凝水下口進(jìn),上口出。c.d.實(shí)驗(yàn)開(kāi)始時(shí),先開(kāi)冷凝水,后加熱。實(shí)驗(yàn)結(jié)束時(shí),先停止加熱,后關(guān)冷凝水。溶液不可蒸干。
【講】錐形瓶中的液體就是蒸餾水,我們?cè)儆孟跛徙y溶液檢驗(yàn)是否含有氯離子。
【實(shí)驗(yàn)演示】蒸餾水加入硝酸銀溶液 實(shí)驗(yàn)室制取蒸餾水1-3 【投影小結(jié)實(shí)驗(yàn)】實(shí)驗(yàn) 現(xiàn)象 實(shí)驗(yàn)加硝酸銀溶液有白色沉淀產(chǎn)生,滴入幾滴稀硝酸和幾滴硝酸在試管中加入少量自來(lái)水,、1
且沉淀不溶解 銀溶液。℃100加熱,燒瓶中水溫升高到燒瓶中加入約100 mL、在2體積的自來(lái)水,再加入幾1/3 沸騰,在錐形瓶中收集蒸餾水,如圖連接好裝置,向冷凝管中通入冷)或碎瓷片(粒沸石卻水。加熱燒瓶,棄去開(kāi)始餾出的總分液體,用錐形瓶收 液體,停止加熱10 mL 集約加硝酸銀溶液于蒸餾水中,無(wú)沉然后滴入幾滴稀硝酸取少量收集到的液體加入試管中,、3 共 頁(yè)3 第 頁(yè)6
淀 和幾滴硝酸銀溶液 【思考】、為什么冷卻水通入方向與被冷凝蒸氣流向相反?)為了使蒸餾出的蒸氣與冷卻水長(zhǎng)時(shí)間充分接觸,帶走盡可能多的熱量(、為什么溫度計(jì)水銀球的頂端要與圓底燒瓶支管下沿處于同一水平線?2對(duì)于蒸餾來(lái)說(shuō),只有精確控制蒸餾的溫度才能達(dá)到分離提純的目的,而蒸餾燒瓶支管口的溫度正是被蒸餾變?yōu)闅?)體某組分的溫度,故溫度計(jì)水銀球頂端要與圓底燒瓶支管下沿處于同一水平線、在日常生活中,我們應(yīng)用蒸餾的方法可以將海水淡化,或制造無(wú)水酒精。若采用蒸餾的方法分離酒精和水的混)酒精沸點(diǎn)低,先蒸出的是酒精。(合物,先蒸餾出來(lái)的物質(zhì)是什么?、從這個(gè)實(shí)驗(yàn)中,大家可以看出蒸餾適用于什么類型的混合物的分離?4
液態(tài)混合物中,沸點(diǎn)不同,除去難揮發(fā)或不揮發(fā)的物質(zhì)。:)蒸餾的使用范圍4(【投】加熱是為了獲得溶液的殘留物時(shí),要用蒸發(fā);加熱是為了收集蒸氣的冷凝液體時(shí),(【思考】蒸餾與蒸發(fā)的區(qū)別:)要用蒸餾【過(guò)渡】在日常生活中,有時(shí)我們的衣服粘了油漬,可以用汽油擦洗,這就是萃取的應(yīng)用。接下來(lái)我們學(xué)習(xí)另外的 一種分離方法,叫做萃取與分液。、萃取2【板書(shū)】 【過(guò)】我們先來(lái)認(rèn)識(shí)這個(gè)新的儀器:分液漏斗。【展示儀器】分液漏斗的組成,分液漏斗的活塞、蓋子同漏斗本身是配套的。使用漏斗 前要檢驗(yàn)漏斗是否漏水。方法為:關(guān)閉活塞,在漏斗中加少量水,蓋好蓋子,用右手壓 住分液漏斗口部,左手握住活塞部分,把分液漏斗倒轉(zhuǎn)過(guò)來(lái)用力振蕩,看是否漏水定義:利用某溶質(zhì)在互不相溶的溶劑中的溶解度不同,用一種溶劑把溶質(zhì)從它(1)【投】
與另一種溶劑組成的溶液中提取出來(lái),在利用分液的原理和方法將它們分離開(kāi)來(lái)。【講解+實(shí)驗(yàn)演示】我們通過(guò)實(shí)驗(yàn)來(lái)解釋萃取的定義,我們知道碘單質(zhì)在水中的溶解度 頁(yè)6 共 頁(yè)4 第
飽和碘水,倒入分液漏斗中。接著,按照萃取的定義,我們10ml不大,碘水呈黃棕色。碘是溶質(zhì),水是溶劑。取 要用另一種溶劑加把溶質(zhì)碘從碘水中提取出來(lái),這另外一種溶劑的選擇要符合一些條件,)萃取劑的選擇:2(【投】 溶質(zhì)在萃取劑的溶解度要比在原溶劑(水)大。a.萃取劑與原溶劑(水)不互溶。b.萃取劑與溶液不發(fā)生發(fā)應(yīng)。c.【講解+實(shí)驗(yàn)演示】那么,我們根據(jù)這些條件可以選擇了四氯化碳,由于碘在四氯化碳的溶解度比較大,所以我們就可以了,進(jìn)行振蕩。請(qǐng)大家注意振蕩的操作:用右手壓住分液漏斗口部,左手握住活塞部分,把分液漏4ml加入
(斗倒轉(zhuǎn)過(guò)來(lái)用力振蕩,注意放氣怎么。振蕩后將分液漏斗放在鐵架臺(tái)上靜置。)強(qiáng)調(diào)放氣的重要性【講解】靜置后,大家發(fā)現(xiàn)漏斗中的液體分為兩層,下層為紫紅色,這一層為碘的四氯化碳的溶液。上層溶液顏色
變淡了,證明碘水中的碘已經(jīng)被萃取到四氯化碳中了,達(dá)到了碘和水分離的目的,這就是萃取。)。。。勺子舀,吸管吸,(【引導(dǎo)】大家想想,萃取后,如何分離?比如湯上面的油層是怎樣弄走的?【講】我們?cè)囅胍幌拢刹豢梢韵朕k法使湯使下面流走,讓油剛好留在容器中。容器下面有通道,湯從下面流走,在湯剛好流完時(shí),關(guān)閉通道,這樣湯和油不就分開(kāi)了嗎,這正好符合分液漏斗的結(jié)構(gòu)。、分液3【板書(shū)】,為什么?【講解+實(shí)驗(yàn)演示】最后一步,就是把四氯化碳層和水層分開(kāi),這就是分液。首先,打開(kāi)蓋子(塞子)(平衡大氣壓)將活塞打開(kāi),使下層液體慢慢流出。漏斗下端口靠燒杯壁。上層液體從上口倒出,為什么?(防止
上層液體混帶有下層液體)【投影總結(jié)】
定義:把兩種互不相溶的液體(且密度不同)分開(kāi)的操作(1)【板書(shū)】萃取與分液的步驟: 檢驗(yàn)分液漏斗是否漏水a(chǎn).加入溶液,加入萃取劑,振蕩b.頁(yè)6 共 頁(yè)5 第
靜置分層c.分液d.(四個(gè)步驟)以及掌握萃取與分液的操作步驟。,(三個(gè)條件)大家要掌握的是萃取劑的選擇通過(guò)這個(gè)實(shí)驗(yàn),【小結(jié)】
附:板書(shū)設(shè)計(jì):、蒸餾、萃取和分液
(二)、蒸餾1、萃取2、分液3 萃取與分液的步驟:4.分液 d.靜置分層 c.加入溶液,加入萃取劑,振蕩 b.檢驗(yàn)分液漏斗是否漏水a(chǎn).五、教學(xué)反思本節(jié)學(xué)習(xí)了混合物的分離和提純的基本操作:蒸餾、分液和萃取,在實(shí)驗(yàn)室上這節(jié)課充分的調(diào)動(dòng)了學(xué)生學(xué)習(xí)的興趣和積極性,雖然準(zhǔn)備實(shí)驗(yàn)很麻煩,但提高了課堂效率,不用再另找時(shí)間做實(shí)驗(yàn)。學(xué)生分組實(shí)驗(yàn)并合作探究,在老師的引導(dǎo)下完成教學(xué)重點(diǎn)內(nèi)容——蒸餾、分液和萃取的基本操作,并通過(guò)親身實(shí)踐進(jìn)一步領(lǐng)會(huì)了蒸餾、分液和萃取法,突破了本節(jié)課的難點(diǎn)——蒸餾、分液和萃取的基本操作原理和注意事項(xiàng),在探究實(shí)驗(yàn)的過(guò)程中學(xué)生也提升了,還有許多分離和提純的方法,化學(xué)學(xué)的科學(xué)素養(yǎng)。在化學(xué)實(shí)驗(yàn)和科學(xué)研究中利用物質(zhì)的,等等。此外,如分餾、層析整堂課學(xué)生求知旺我們將在今后的學(xué)習(xí)中慢慢接觸到。,應(yīng)用也十分廣泛,特殊性質(zhì)來(lái)分離和檢驗(yàn)物質(zhì)的方法也很多
盛,復(fù)雜的知識(shí)變得簡(jiǎn)單化,親自動(dòng)手操作,加深了印象,提高了能力。頁(yè)6 共 頁(yè)6 第