Thuật ngữ tiếng Anh chuyên ngành Hóa học: Phần 1

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Trước những phát triển khoa học diễn ra hằng ngày với một tốc độ chóng mặt trên thế giới, nhu cầu nắm bắt, tìm hiểu và tiếp cận những thành tựu này là nhu cầu cấp thiết nhất. Tuy nhiên giới sinh viên và học sinh cũng như những người làm công tác khoa học đôi lúc vẫn còn bị rào cản ngôn ngữ che chắn nhất là Tiếng Anh khoa học. Để đáp ứng nhu cầu đọc hiểu tiếng anh khoa học cơ bản, chúng tôi biên soạn quyển “Tiếng Anh chuyên ngành Hóa học” này. Phần 1 trình bày những khái niệm, định nghĩa và định luật căn bản về hóa học. Mời các bạn cùng tham khảo để nắm nội dung chi tiết.

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Nội dung Text: Thuật ngữ tiếng Anh chuyên ngành Hóa học: Phần 1

C H A U V A N TRUNG sj i u iii i i i m j j i un i ci i r] HO A HOC N H A X U A T B A N G I A O T H O N G V A N TAI
T I E N G A P iH C f f l J Y E N N G A N H
KS. C H A U V A N TR U N G CHUYEN NGANH & (Basic English for Chemistry) N H A X U A T B A N G IA O T H O N G V A N T A I
LUYEN KY NANG DOC HIEU & DICH THUAT TIENG ANH CHUYEN NGANH ■ ■ HOA HOC Chau Van Trung Chiu track nhiem xuat ban TS N G U YEN XUAN THUY Bien tap NGO THANH LOAN Sita ban in THANH LOAN Bia LAM VU NHA XUAT RAlfGIAO THONG VAN TAI In 700 cuon, kho 16 x 24cm tai Nha in Thanh Nien, 62 Tran Huy Lieu - Q.PN-TP. HCM - DT : 8440038 - 8445308. Giay phep xuit ban so 230/XB-QLXB do Cue Xuat ban cap ngay 3/03/2005. Giay trich ngang so 70/XB ngay 05/9/2005. In xong v& nop luu chieu qui IV n&m 2005.
LCJl n o i d a u TrUdc nhufng p h it trien khoa hpc d iin ra h in g ng^y vdi mpt toe dp chdng m3t tren the gidi, nhu cau n im b it, tim hieu tiep can nhufng thcinh ti/u n iy la nhu cau cap thiet nhat. Tuy nhien gidi sinh vien hoc sinh cung nhu nhQng ngifdi lim cong t ic khoa hpc doi luc v ln con bj rao c in ngon ngO che c h in nhat l i Tieng Anh khoa hpc. De d ip ufng nhu cau dpc hieu tieng anh khoa hoc cd b in , chung toi bien soan quyen "Tieng Anh chuyen nganh Hoa hpc" n^y. Sich gom 20 chu diem trinh bay nhOng k h ii nipm, dinh nghTa djnh luat c3n b in ve Hoa hoc. Md dau mdi chu diem co phan gidi thipu muc dfch yeu c iu , phan bo cuc b in g tieng Anh va hudng d in doc hieu b ln g tieng Vipt, ke tiep la c ic noi dung c3n b in co chufa trong chu diem. De ren ky nSng doc hieu tieng Anh Hoa hpc, sau m6i npi dung trong diem chung toi co phan chu g iii tC vi/ng va bai dich m lu - cuoi chu diem la phan bai tap thi/c hanh. Cuoi / sich cd phan phu luc danh muc tC vi/ng tieng Anh Hoa hoc n h im giup ban f dpc hp thong hoa cac thuat ngO chuyen nganh can thiet. Bi/dc dau, du het sufc cd g in g nhi/ng sich khong kh6i trin h dupe nhufng sai sdt ngoai y muon; rat mong nhan di/pc nhufng gop y chan tinh cua ban doc. T a c g ia . v a n h o m CQng ta c
BA5IC CONCEPTS cAc khAi m co bAm iCm Mgc BICH y £u cAu - O b je ctiv es b6 CUC - L a y o u t 1.1 To classify m a tter into types to 1.1 Classification of Matter m ake the w e ath o f information 1.2 Properties about m a tter m anageable 1.3 Matter and Energy 1 .2 To use pro p erties to help identify substances 1.4 Chemicall Symbols 1 .3 To distingguish b etw een m atter 1.5 The Periodic table and e n e rg y, as w e ll as am ong 1.6 Laws. Hypotheses, and Theories m atter, mass, and w e ig h t 1 .4 To w rite sym bols for the im p o r tant e lem en ts and names o f these elem en ts from the symbols 1 .5 To begin to classify the elem ents in a systematic manner. To identifu periods, groups, and sections of the p eriodic table by nam es ans num ber 1 .6 To d is tin g g u is h am ong la w s , hypothess, and thearies Jiudng ddn doc hieu muc dich yeu cau vd bo cuc 1.1 Phdn loqi vat chat thanh tiCng loqi de tqo ra thong tin vat lieu phong phu, 1 .2 D ung tinh chat de giup xdc dinh vdt chdt, 1.3 Phdn biet giUa vdt chdt vd ndng luqng cung nhu vat chdt, khdi luqng vd trong luqng, 1.4 Viet ky hieu cho nguyen to quan trong vd ten cua nhitng nguyen to tit cdc ky hieu, 1 .5 Loqi cdc nguyen to trong m 6 t he thong phdn loqi de xdc dinh chu ky, phdn nhom vd chia nho bang phdn loqi bai ten vd so, 1 .6 Phdn biet giQa cdc quy ludt, gid thuyet vd ly thuyet. 1.1 Phdn loqi vdt lieu, 1.2 Tinh chat, 1.3 Vat chat vd ndng luqng, 1.4 K y hieu hoa hoc, 1 .5 Bang he thong tudn hoan cdc nguyen to, 1 .6 Cdc quy ludt, gid thuyet vd cdc ly thuyet. 7
Topic I: /insic concepts Introduction to chemistry C hem istry is the study of m atter and energy M atter includes all the m aterial things in the universe In S ection 1 1 . you will learn to classify m atter into various ty p e s — elem ents com pounds, and m ixtures based on com position P ro p e rtie s-th e characteris tics by w hich sam ples of m atter may be identified are discu ssed in Section 1 2 E nergy m ay be defined as the ability to do work. W e often ca rry out chem ical reactions for the sole purpose of changing energy from one form to a n o th e r for ex ample, we pay large sum s of m oney for fuels to burn in our hom es or cars The re la tionship betw een energy and m atter, an im portant one for ch em ists, is explore d in S e c tion 1 3 S ym b ols in tro d u ce d in S e ction 1.4, are used to re p re s e n t the e le m e n ts The perio d ic table, in tro d u ce d in S e ction 1 5, groups e le m e n ts w ith s im ila r p ro p e r ties C he m ica l sym b o ls and the p erio d ic table are both d e s ig n e d to d e c re a s e the e ffo rt required to learn a great deal of ch em istry S ection 1 6 p re se n ts s c ie n tific law s h y potheses. and th e o rie s that g en eralize and explain natural p he n o m e n a For convenience, ch em istry is often divided into the follow ing five su b -d is c ip lin e s organic chem istry, inorganic chem istry, analytical chem istry, p hysi-ca l c h e m is try and b iochem istry O rganic chem istry deals with m ost com pounds of carbon T hese c o m pounds are introduced syste m a tically in C hapter 19. Inorganic chem istry deals with all the elem ents and with com pounds that are not defined as o rganic A n alytical c h e m istry involves finding w hich elem ents or com pounds are p re sen t in a sam ple or how m uch of each is pre sen t Physical chem istry deals with the p ro pe rtie s e sp e cia lly q u a n titative (m easurable) pro pe rtie s of substances Biochem istry deals w ith the ch e m istry of living things These su bd ivision s of ch em istry are som ew hat arbitrary A ch em ist s p e cia lizin g in any one of the first four subdivisions uses all of the first four and often b io ch e m istry as well A b iochem ist uses all five specializations For exam -ple, the m odern o rganic c h e m ist often uses inorganic com pounds to convert starting m aterials to d e sire d p ro du cts and then analyzes the products and m ea-sures their p roperties In addition m any o r ganic chem ists now are investigating com pounds of biological interest The im portance of science in general and of ch em istry in p articula r in our e v e ry day lives can hardly be overstated For exam ple, color television, c o m p ute rs and the modern copy m achines all stem from chem ical advances of the past few d eca de s (Color TV requires co m p ou nd s that glow intensely in red blue or green w hen b om b a rd e d with electron beam s The m odern com puter w orks with ch ip s m ade from sp e c ia lly treated m etalloids. Copy m achines require m aterials that "re m e m b e r’ how m uch light has fallen on them .) However, today s and tom orrow s chem ists are still faced w ith m o n u m ental tasks cleaning up the e nviro n m e nt and p roviding su ffic ie n t food for an e v e r growing w orld population to m ention just two. Table 1.1 C lassification of M atter Pure substances Kl oments C o mp o un d s Mixtures Het erogeneous mixtures Ho mo ge n e o u s mixtures ' soluti ons) 8
Topic 1: Basic concepts Chu thich tCf - cum t£f va huong dan dpc hieu - O rganic ch e m istry: hda In7a co - Physical ch em istry: hda ly - In orga n ic ch e m istry: hda vd co - B iochem istry: hda sinlt - A n a ly tic a l ch e m is try : hoa phan licit Nhap mon hoa hoc Hoa hoc la stf nghien ctfu ve vat chat va ndng htqng. Vat chat bao gom tat cd cdc vat lieu trong vu tru. Trong muc 1.1 ban se hoc cach phdn loqi vat chat thanh cac dang khac nhau nhu nguyen to, hap chat, lion hap dtfa tren cdc thanh phan. Tinh chat, dac tinh cua vat chat co the dtfqc xdc dinh vd lliao luan trong muc 1.2 . Ndng luqng cd the ditqc xdc dinh bdi Itlid ndng thtfc luen cong. Chung ta thildng thtfc hieu phdn ling hoa hoc dp (hay doi ndng htqng lit dang nay sang dang khac, vi du. chung ta trd mot so lien Ian mua nltien lieu de dot trong sinh lioqt gia dinh vd trong xe hoi. Mdi quan lie giita ndng htqng vd vat chat rat quan trong trong lioa hoc ditqc gidi thich trong muc 1.3. Cdc ky hieu ditqc gidi thieu trong muc 1.4 ditqc stf dung de mo ta cdc nguyen to hoa hoc. Bang phdn loqi ditqc gidi thieu trong muc 1.5. nhom nguyen to vdl cdc tinh chat titang ling. Cd hat ky liieu lioa hoc vd bang phdn loai ditqc thiet lap de gidm no hie dtfqc yen can de nghien ciiu mot so htqng Ion hoa chat. Muc 1.6 gidi thieu cdc quy ludt, gid thiet, ly thuyet khoa hoc de long qudt lioa rd giai tliicli hien htqng til nhien. De cho tliiidn hen. hoa hoc ditqc cltia thanh ndm nhom: hoa ln?u co. lioa cd ca, lioa phdn licit, hoa ly i d hoa sinh. Iloa hitu co lien quan den hdu hel cdc hop chat cua car bon. nhilng hop chat nay se ditqc gidi thieu trong chitong 19. Hoa vd, co hen quan den phdn Ion cdc nguyen to id cdc hop chat ina Ithong phai Id chat hitu co. Hoa phdn tich Id tiin cdc nguyen to hay cdc hop chat cd trong mau hoac dinh litqng chung. Hoa ly lien quan den so tinh chat (do litdng) tinh chat cua cdc chat. Hoa sinh lien quan den hoa hoc cua sinh vat. Stf phdn cltia mon hoc nay cd sit ngau nhien. Mot chuyen gia hoa hoc chuyen ve mot trong bon nganh dau tien cd the dp dung ditqc bon nganh dau tien va cd nganh hoa sinh. Mot chuyen gia hoa sinh sii dung ndm nganh hoa tren. Vi du, mot nha hoa hu'u co luen dqi tlutong sit dung cdc hop chat co ca de chuyen hoa cat chat thanh san pham niong muon vd sau do phdn tich san pham va xdc dinh tinh chat cua chung. Trong sit cdng them do, bay gio nhieu nha lioa lit?u co lai nghien ciiu cdc hop clidt cua cdc sinh cat ditqc quan tdm. Sit quan trong cua khoa hoc noi chung cd ciia hoa hoc noi n en g trong cuoc song hang ngay kho cd the noi het ditqc. Vi du, ti vi mau. M ay vi tinh vd may sao cliep luen dqi, tat cd deu xuat phdt tit stf phat tnen cua hoa hoc trong vai thap ky qua. (Ti vi mdu doi lioi hop chat cd ctfdng do mdu do, xanlt Id hay mdu xanh da trdi khi bdn phd chum tut electron. May tinh luen dqi lain d ec edi "chip" ditqc lam lit cdc cat hen dqc biet 1a a kim. May sao chep. dot hoi cat lieu cd the "nha” ditqc bao nhieu anh sang rcri tren chung. Tuy nhien. cdc nha hoa hoc horn nay vd titang lai can dang dot mat edi nluem vu Ian do Id lam sach moi trtfdng cd cung cap du tlutc pham cho sit gia tang dan so the gidi ' a
Topic 1: Basic concepts Chu diem 1.1: Classification of Matter________________________________ M atter is defined as anything that has m ass and occupies space All the m ate rials in the world are com posed of a few more than a hundred elem ents. E lem ents are the sim p lest form of m atter and cannot be broken dow n ch e m ic a lly into s im p le r stable substances. They can be thought of as building blocks for everythin g in the universe The sam e elem ents that m ake up the Earth also m ake up the M oon, as show n by actual analysis of Moon sam ples. M oreover, indirect evidence obtained from analysis of light from stars shows that the rest of the universe is com posed of the sam e e le m ents. C learly the num ber of d ifferent com binations of elem ents m ust be huge to get all the varieties of m atter in the universe. But elem ents can com bine in only tw o fu nd a m entally differen t ways: by physical changes to form m ixtures or by ch em ica l changes to produce com pounds. C hem ical changes, also called chem ical reactions, change the com position (or structure) of a substance. Physical changes do not alter the co m position. The breaking of glass into sm all pieces is an exam ple of a physical change. The glass still has the sam e com position and the sam e p’roperties as before, but its external form is changed. The burn-ing of charcoal (m ostly carbon) in air (or in pure oxygen) to get carbon dioxide, a colorless gas, is an exam ple of a ch em ica l reaction. Not only the form of the m aterial but also its com position has changed. The gas has both carbon and oxygen in it, but the charcoal had no oxygen. If a sam ple of m atter cannot be broken down into sim pler su bsta nce s by ordinary chem ical m eans, the sam ple is an elem ent. [O rdinary ch em ica l m eans in clu de s any m ethods except nuclear reactions (C hapter 20).] An elem ent has a definite set of p ro p erties. A com pound is a c h e m ica l co m b in a tion of e le m e n ts th at has its own set of properties and a d efin ite com position. For exam ple, pure w ater o btained from any natural source contains 88.8% oxygen and 11.2% hydrogen by m ass C om pounds can be separated into their constitu en t elem ents only by chem ical reaction Snapshot Review - On tap nhanh *- We classify m atter so that we can learn the general properties of each type to enable us to a nsw er specific questions about individual sam ples *■ All substances have definite com positions. A. Does the com pound hydrogen peroxide have a definite c o m p o sitio n 7 • Chung ta phdn loqi vat chat de cd the nghien ciiu cac tinh chat chung cua tung loqi nham cung cap cho chung ta cau tra lai nhUng cau lioi ve cdc mau rieng biet • Tat cd cdc chat cd thanh phdn xac dinh A. Cd phdi liqp chat hydrogen peroxide cd mot thanh phan xdc dinh khong f Chu thich tQ - cum to va hifdng dan dpc hieu - chem ical changes: cdc thay doi hda hoc - chem ical reactions: cdc phan ting hoa hoc - physical changes: cdc thay doi vat ly - compound: hap chat - d e fin ite com position: cac thanh phdn, cdc hon hap xdc dinh 10
Topic 1: Basic concepts Phan loai vat chat Vat chat la tat cd cdc vat cd khoi luqng chiem cho trong khdng gian. Tat cd cdc vdt lieu tren the gidi duac tqo ra ti/ it ham 100 nguyen to. Cdc nguyen to dan gian nhat cua vdt chat thi khdng the phdn chia thanh cdc nguyen to dan gian lion, chat on dinh. Chung cd the duac nghi la cdc thanh phdn ca ban tqo nen moi thit trong vu tru. Cdc nguyen to cung loqi tqo nen trai dal cung tqo nen mat trang, duac cluing minh bai phdn tich thtfc te cua mau vdt lieu tren mat trang. Ilan the ni2a, bang cluing gian tiep dat duac tit stf phdn tich anh sang cua cdc ngoi sao cluing minh rang phan con lai cua vu tru dtfqc tqo ra cung tit cdc nguyen to gidng nhtf d tren. Ro rang so Itfong cua stf kit hap khac nhau cua cdc nguyen to la rat Idn de tqo nen stf khac nhau cua vat chat trong vu tru. Nhtfng cdc nguyen to cd the ket hap tlieo hai cach ca ban sau: bang cdch thay doi vat ly de tqo thanh hon hap hodc thay dot hda hoc de tqo thdnli hap chat. Stf thay doi hoa hoc dtfqc goi la phdn ting hda hoc, lam thay doi thanh phdn cau true cua vat chat. Stf thay doi vat ly khdng lam thay doi thanh phdn hda hoc. Stf va gitang tqo thanh nhtfng mieng nho la mot vl du cua stf thay doi vat ly. Guang (kinh) van cd tlianh phdn vd tinh chat nhtf tritdc do nhUng hinh dang ben ngoai bi thay doi. Sit dot chdy than (lidu het la carbon) trong khdng khi (hoac trong oxy tinh khiet) de tqo nen cacbon dioxit, mot khi khong mdu 1 mot vi du cua mot phdn tfng hda a hoc. No khdng chi lam thay doi vdt chat md con lam thay doi cd thanh phdn. Khi sinh ra cd cd carbon vd oxy. con than tlii khdng cd oxy. Neu mot mdu vat chat khdng the vd ra tlianh cdc chat dan gian hon bai cdc phtfang phdp hda hoc thong thtfdng, mdu la mot nguyen to [phtfang phdp hda hoc thong thtfdng gom bat ctf phtfang phdp nao ngoqi trit phdn tfng hat nhan (chi/cfng 2 0 )/ Mot nguyen to cd mot so tinh chat xdc dinh. Mot hop chat la mot stf kit hap hda hoc cua cdc nguyen to cd cdc tinh chat vd thanh phan xdc dinli. Vi du, ntfdc tinh khiet trong thiin nhien chtfa 88 ,8% oxy va 11,2V ve khdi luqng. Hap chat cd the ditqc tach ra thanh cdc nguyen to chi c bdng phtfang phdp hda hoc. Chu diem 1.2: Properties Every su bsta nce has a definite set of properties. Properties are the characteris-tics by w hich we can ide ntify som ething. For exam ple, we know that pure w ater is a co lo r less, odorless, ta ste le ss substance that is a liquid under the conditions usually found in an o rdinary room W ater puts out fires, and it dissolves sugar and salt. Liquid w ater can be changed into a gas (called w ater vapor or steam ) by heating it, or into a solid (ice) by cooling it. Salt has a d ifferent set of properties than w ater does; sugar has yet another set C h em ical p ro perties are the ch a ra cte ristic w ays a su bsta nce can react to p ro duce o the r su b sta n ce s Physical properties are the ways a su bstance can be id e n ti fied w ithout ch a n g in g its ch aracte ristic com position. For exam ple, w ater can react with very active m eta ls to produce hydrogen and a nother com pound. T hat rea ctivity is a ch em ica l p ro pe rty of w ater. W ater can also freeze to ice at 0°C (equal to 32°F) or it can e vaporate to w ater vapor, n either of w hich changes it from H20 . T hese are p h y s i cal pro pe rtie s of w ater. Som e p ro p e rtie s of a sam ple of a substance depend on the q uantity of the sam ple These p ro p e rtie s are called extensive properties. For exam ple, the w eight of a solid sam ple d ep en ds on how m uch of the substance is present. O ther p roperties, such as II
Topic 1: Basic concepts color and taste, do not depend on how m uch is present These properties are know n as intensive properties. Intensive properties are m uch m ore u sefu l for ide ntifyin g sub stances Som e of the m ost im portant intensive p roperties that ch e m ists use to ide ntify s u b stances are ones that they m easure: they are called q u a ntita tive p ro p e rtie s T w o such p ro pe rtie s are the free zing point and the norm al boiling p o in t of a s u b s ta n c e w hich are the te m p era ture s at w hich a liquid freezes to form a solid and boils to form a gas under norm al a tm o sph e ric co nditions, respectively. W e w ill d is cu ss q u a n tita tive p ro p e r ties in m ore detail in C ha pter 2. W e can d istin gu ish co m p ou nd s from m ixtures because of c o m p o u n d s 's c h a ra c te r istic properties. M ixtures have p roperties like those of their co n s titu e n ts The m ore of a given co m p on en t p re sen t in a m ixture, the more the m ixtu re 's p ro p e rtie s w ill resem ble those of that co m ponent. For exam ple, the m ore sugar we put into a gla ss of w ater, the sw ee te r is the solution that is produced An e xp e rim e n t w ill illustrate how properties are used to d is tin g u is h b etw e en a c o m pound and a m ixture. W e place sm all sam ples of iron filings and p o w de red su lfur on separate w atch g la sses to in ve stiga te th e ir properties. W e note th a t both are solids We place the sa m p le s in separate te st tubes and then hold a m ag ne t b eside the first tube. W e find that the iron is attracted to the m agnet. W hen we hold the m agnet next to the tube w ith the sulfur, nothing happens; the su lfur is not attracte d by the m agnet W hen we pour carbon disulfide, a colorless, flam m able liquid, on the sul fur sam ple the solid sulfur disappears, and the liquid turns yellow. The sulfur has dissolved, form ing a solution w ith the carbon disu lfide W hen we pour carbon d isu lfide on the iron n o th ing happens; the iron stays solid, and the liquid stays co lo rle ss If we had large pieces of each elem ent, we could pound them with a ham m er and find that the su lfu r is brittle and easily pow dered but that the iron does not easily break into sm all p ieces Iron is m alleable that is, it can be pounded into various shapes. T able 1.2 lists the p ro pe rtie s discussed so far of the two elem ents. N ext we pour som e iron filings and som e pow dered su lfur into a large test tube and stir them together. The sam ple appears to be a dirty yellow , but if we look closely, we can see ye llo w sp ecks and black specks. If we hold a m ag ne t next to the test tube, the black p article s (with som e yellow par-ticles clinging to them ) are a ttracte d by the m agnet W hen we pour som e carbon d isulfide on the sam ple, the liquid tu rn s yellow We pour off that liq uid and pour on m ore carbon d is u lfid e u ntil no ye llo w so lid re m ains in the sam ple W hen we evaporate the carbon disu lfide in a fum e hood we get a yellow solid again If we place a m agnet next to the black m aterial left in the large test tube, we find that it is attracted to the m agnet It seem s that m ixing the tw o sa m p le s Table 1.2 Some Properties of Iron, Sulfur, and an Iron-Sulfur Compound Iron Sulfur Iron-Sulfur Com pound S olid S o lid S o lid S h iny Dull Dull M agnetic N o t m agnetic Y e llo w Black N o t m agnetic B lack M a lle a b le B r ittle B r ittle Insoluble in carbon Soluble in carbon Insoluble in carbon d isu lfid e d isu lfid e d is u lfid e 12
Topic 1: Basic concepts of elem ents has not changed their properties. The sulfur is still yellow and still soluble in carbon d isu lfide ; the iron is still black and still m agnetic. The two ele m e n ts have retained th eir p ro pe rtie s and their identities; they are still elem ents. This com bination of the two is a m ixture. A m ixture does not have a d efin ite co m p ositio n, and it has properties related to the properties of its com ponents. Now we place two new, carefully m easured sam ples of iron filings and pow dered sulfur in another large test tube and heat the m ixture strongly with a Bunsen burner. After a tim e, a red glow appears in the bottom of the tube and gradually spreads th ro ug h out the sample. This is evidence of a chem ical reaction. Some sulfur escapes into the gas phase because of the heat and then deposits on the test tube wall. A black solid results from the chem ical reac tion. W hen we rem ove the solid from the test tube (we may have to break the tube to get it out), we can pulverize the solid with a ham m er that is. it is brittle. If we try to dissolve the m aterial in carbon disulfide, it does not dissolve. If we bring the m agnet close to it, it is not attracted. This m aterial has its own set of prop erties: a dull black color, brittleness, insolubility in carbon disulfide, lack of attraction to a magnet. It is a com pound a chem ical com bination of iron and sulfur. Snapshot Review - On tap nhanh *- E xtensive p ro pe rtie s depend on how m uch sam ple is present; intensive p ro p erties do not Intensive pro pe rtie s are useful for identifying substances. Each su bsta nce has its own characteristic set of properties. A C on side r the statem ent: “There is 1 liter (L) of colorless soda in the can." W hich of the two pro pe rtie s is intensive and w hich is extensive? B. A ce rta in fa m ilia r su bstance freezes at 0°C. Does this pro pe rty help ide ntify the substa nce ? • ('dc tinh chat bao quat phu thudc vdo so Itfong mdu (long cd; con cac tinh chat tang ctfdng thi khong. • Cac tinh chat tang ctfdng hi'tu dung trong viec nhdn biet cdc clidt. • Moi chat cd tap hop cdc dqc tinh cua rieng no. A. Khdo sat rnenh de "Co 1 lit (I) soda khdng mdu trong thung chtfa". Tinh chat nao trong hai tinh chat Id tinh chat tang ctfdng vd tinh chat nao la tinh chat bao quat? B. M ot chat quen thuoc dong dqc tai 0°C. Tinh chat nay cd giup nhdn biet chat do hay khdng? Chu thich to - cum to va hUdng dan dpc hieu heterogeneous m ixtures: hon hop di the - substances: cdc chat homogeneous m ixtures: lion hop dong the - solutions: cdc dung dich - physical properties: cac tinh chcit vdt ly - m ixtures: cdc hon hop - chem ical properties: cdc tinh chat lioa hoc - m alleable: cd the uon cong - exten sive p roperties: cdc tinh chat long quat - properties: cdc tinh chat - in te n s iv e properties: cdc tinh chat tang ctfdng - dissolved: hda tan. phdn gidi - q u a n tita tiv e properties: cdc tinh chat ve dinh luqng 13
Topic !: Basic concepts Tinh chat Moi chat cd moi so tinh chat xdc dinh. Tinh chat la cac dqc tinh ma chung ta cd the nhdn ra dtfqc. Vi du, chung ta biet ntfdc tinh khiet khdng co mdu, khdng rnui, khdng vi va d dang long trong dieu kien thtfdng (phdng). Ntfdc dap tdt Ida, no hda tan dtfdng va muoi. Ntfdc cd the chuyen doi thanh hoi (dtfqc goi la hoi ntfdc) khi cung cap nhiet, hay d dang rdn (da) khi lam lanh. Muoi cd tinh chat khac ntfdc, dtfdng cung cd tinh chat neng. Tinh chat hda hoc Id dac tinh ma mot chat cd the phdn ilng de tqo thanh san pham la mot chat khac. Tinh chat vat ly la cach ma mot chat cd the dtfqc nhdn ra ma khdng lam thay doi thanh phan dac trtfng cua no. Vi du, ntfdc cd the phan tfng vdi rat nhieu kim. loai hoqt dong de tqo thanh hydro vd hqp chat khac. Hoat tinh do la mot tinh chat lioa hoc cua ntfdc. Ntfdc cd the llidrih dd d 0 "C (bang 32"F) hay no cd the bay hot thanh hoi ntfdc ma khdng lam thay doi thanh phan ntfdc. Day Id tinh chat vdt ly cua ntfdc. Mot so tinh chat cua mot mau cua mot chat phu thuoc vdo so Itfqrig mdu. Tinh chat nay dtfqc goi la tinh chat tong quat (chung). Vi du, trong Itfong cua mot mdu chat rdn phu thuoc vdo so Itfong chat hien dien. Tinh chat khac nhtf mdu, vi khdng phu thuoc vdo so Itfong chat hien dien. Nhilng tinh chat nay dtfqc xem nhtf 1a tinh clidt rieng Tinh chat rieng nay thi hQu ich cho viec nhan dang cdc chat. Mot so tinh chat tang ctfdng quan trong nhat md nhilng nha hda hoc stf dung de nhan biet cdc chat dd Id dac diem md ho do dtfqc; nhilng dqc diem nay dtfqc goi la cdc tinh chat dinh Itfong. Hai tinh chat nhtf the la diem dong dqc vd diem soi chuan cua mot chat, tile la nliiet do tai dd chat long dong dac de tqo thqnh mot chat rdn vd hda hoi de tqo nen mot chat khi trong cdc dieu kien dp suat binh thtfdng ttfong ling. Chung ta se thdo luan cdc tinh chat dinh Itfong chi tiet hon trong chtfong 2 . Cd the phdn biet cdc hop chat vdi cac hon hqp do bdi cdc tinh chat dac trtfng cua hqp chat. Cdc hon hqp thi cd cdc tinh chat y het nhtf cdc tinh chat cua thtfc the tao nen chung. Thanh phdn dd dtfqc cho hien dien trong mot hon liqp cang nhieu thi tinh chat cua hon hqp dong nhat vdi thanh phdn dd cang nhieu. Vi du, cang cd nhieu dtfang trong mot ly ntfdc thi do ngot dtfqc tqo ra trong dung dich cang Idn. Mot thi nghiem minh hoa cdch md cdc tinh chat dtfqc dung de phdn biet giUa hop dial vd lion hop. Chung la dat cdc mdu bot sal nho vd sulfur bot Iren hai ly tdch roi nhau de ddnh gia dac tinh cua chung. Ltfu y rang cd liai deu d trang that rdn. Dat cdc mau trong cdc dug nghiem neng biet vd giU mot nam chain ben cqnh ong nghiem ihtf nliat Ta thay rang sal bi hut ve phia nam chain. Luc giQ nam chain cqnh ong nghiem cd clitfa sulfur thi khong cd dieu gi xay ra; nhtf vay sulfur khdng bi nam chain hut. Luc dd disulfide carbon, mot chat long de bat hia vd khong cd mau, vao mot mau sulfur thi sulfur dqc bien mat, vd chat long chuyen sang mdu vdng. Sulfur dd bi hoa tan tqo nen mot dung dich vdi disulfide carbon. Luc chung ta do disulfide carbon vao trong sal thi khdng cd dieu gi xay ra; sat van gal trang thai rdn vd chat long van giii trang thai khdng mdu. Neu ta cd cdc mieng Idn cua moi nguyen to thi ta cd the gia chung vdi mot biia ren vd thay rang sulfur cd tinh don vd de bieii thanh bot nhtfng sal thi khdng de dang bi ngdl thanh nhilng mieng nho. Sat cd tinh deo - cd nghia rang no cd the dtfqc gia de chuyen thanh cdc hinh dang khac nhau Hang 1.2 het ke cac dac tinh dtfqc de cap chuyen sdu hon ddnh cho hai nguyen to nay. Ke tiep chung ta do moi it bot sat vd mot it bot sulfur vdo mot ong nghiem Ion hon vd khudy deu cluing. Mdu xuat luen cd mdu vdng nhat, nhtfng neu quan sal k\ ta tha\ rang cd cdc quang vdng vd quang den. Neu giu mot nam chain ke ben mot ong nghiem. thi cdc hat den Ivoi moi so hat cang .rung quanh chung bi hut bdi nam chdm. Luc ta do 14
Topic 1: Basic coticepls disulfide carbon tren mau thi chat long chuyen sang mau vdng. Ia do ra ngoai chat long do va dtfa vao them disulfide carbon cho den khi khdng con chat ran mau vang nao gid lai trong mdu nda. Luc lam hda hai disulfide carbon trong mot ong nung, ta lai nhan duoc mot chat ran mau vdng. Neu dat mot nam chain ke ben vat lieu mdu den d ong nghiem Idn hon, ta thay rang no bi hut ve phia nam chain. Dieu do cd nghla rang hon hqp cua hai man nguyen to khong thay doi tinh chat. Sulfur van gilt mau vdng ra vat co the duac hda tan trong disulfide carbon; sat van gida mdu den va van mang tit tinh. Ilai nguyen to nay van gid dac tinh va nhdng dac trUng chuyen biet cua chung; chung van Id cdc nguyen to. To hop cua liai nguyen to nay la mot hon hop. Mot hon hop thi khdng cd mot hqp chat xdc dinh, no cd cdc dac tinh co lien quan den cdc dac tinh cua moi mot thanh phan. Bay gid chung ta dat hai mdu mdi duac do can than bot sat vd bot sulfur vdo mot ong nghiem Idn hon, nung ndng hon hqp vdi mot den Bunsen. Sau mot khoang thai gian, cd mot chat quang dd xuat hien d day cua ong nghiem vd dan dan Ian rong khap mdu. Day la chdng cd cua phdn ling hoa hoc. Mot so sulfur dd chuyen sang trang thai khi do bdi sdc ndng roi long dong tren tlianh cua ong nghiem Chat rdn mdu den hinh tlianh tit ket qua cua phan ling hda hoc. Luc chung ta loai bo chat rdn klioi ong nghiem (chung la pluii lain be ong nghiem de do no ra ngoai). Ta cd the go chat rdn ra bang cdch dung moi cai bua cd nglila rang tqo do gtdn cho no. Neu chung ta thd phdn gidi vdt chat trong moi disulfide carbon, thi no khong phdn giai duqc. Neu chung ta dua mot nam chain den, no van khdng bi hut. Vat lieu nay cd mot tap hqp cdc dac trUng chuyen biet cua no, mdu den dam, gion, khdng the hda tan trong disulfide carbon, khdng bi hut bdi moi nam chdm. Day la mot hon hqp - tdc la mot to' hqp hda hoc cua sat vd sulfua. Chu diem 1.3: Matter and Energy M atter is a nyth ing that has m ass and occupies space All the m aterial things in the u niverse are com posed of matter, including anything you can touch as w ell as the planets in the solar system and all the stars in the sky. The mass of an object m easures how much m atter is in the object. M ass is directly proportional to w eight at any given place in the universe. If you leave the surface of the Earth, your m ass rem ains the same, but your weight changes An astronaut positioned between two celestial bodies such that their gravitational attractions pull equally in o p posite directions is w eightless, but the astronaut's mass rem ains the sam e as it was on Earth B ecause chem ists ordinarily do their work on the Earth s surface and because m ass and w eight are directly proportional here, many chem ists use the term s mass and weight interchangeably, but you should rem em ber that they differ. Energy is the capacity to do work. You cannot hold a sound or a beam of light in your hand; they are not form s of m atter but form s of energy. The m any form s of e n ergy are outlined E nergy cannot be created or destroyed, but it can be converted from one form to a nother This statem ent is known as the law of conservation of energy. Snapshot Review M atter has m ass and occupies space. *- M ass is a m easure of the quantity of m atter in a sam ple (but e nergy also has a m ass equivalent). A W hich has a greater m ass a large wooden desk or a sew ing needle? 15
Topic / ; Hasic concepts • Vat chat co khoi Itfong va chiem gn7 khoang trong trong khong gian • Khoi Itfong L mot so do ve dqi Itfong vat chat trong mot mdu Inhtfng nang Itfong a cung co mot stf Itfong dtfong vdi khoi Itfong). A. Phdn nao co khoi Itfong Idn hon mot bdri go Idn hay mot cay kim m ay! Table 1.3 Form s of Energy Ile a l C hcm ical N uclear M echanical K in e tic (energy o f m otion) P o te ntia l (energy o f p ositio n ) K le ctrica l Sound K le ctro m a g n e tic ( lig h t) V is ib le lig h t U ltra v io le t X -ra ys G am m a rays In fra re d Radio waves M icrowaves S o la r” ‘ S olar energy is a co m bination of several fo rm s o f light Chu thich tQ - cum tCf va hUcrng dan dpc hieu m atter: vdt chat - energy: ndng Itfong mass: khoi luong - w eig ht: trong Itfong - law o f conservation: dinh ludt bdo toan Vat chat va nang luong Vat chat la bat cd thd gi co khoi Itfong vd cliiem clw trong khdng gian Trong tat ca moi vdt trong vu tru la thanh phdn cua vdt chat, ke cd bat cd dieu gi ma ban cd the so md cling nhtf cdc hdnh tinh trong thai dtfong lie vd tat cd ngoi sao tren bdu trdi. Khoi Itfong cua mot vat do do Idn cua vdt chat. Khoi Itfong ty le thudn cat trong ItfOng o' tai bat cd noi nao trong vu tru. Neu ban dl chuyen be mat cun trdi dot. thi klioi Itfong cua no rdn gi/T khong doi. nhtfng trong htqng cua no thay doi Mot nha du lianli vu tru dung glda hai thien the sao cho sdc hut trong trtfong cua chung bang nhau to theo chieu doi ngliich tin ngtfdi nay a trang thai khong trong Itfong. tu\ nhien khoi hionii ciiu nha du hanh vu tru do rdn gu 7 khong dol y het nhtf tren mat dot Hoi t i cac nha hoa hoc thtfc hien cdng viec cua lio mot cdcli binh thtfdng tren be mat trdi dat ca b
Topic 1: Basic concepts Ndng Itfong Id kha nang thtfc hien cong Han khdng the gid dm thanh mot chum tin nang trong toy dtfqc; cluing khdng phai la mot dang rat chat nhtfng Id mot dang cua ndng Itfong. Nhieu dang nang Itfong dtfqc trinh bay trong bang 1.3. Nang Itfong khong the dtfoc tqo ra liodc khong the bi mat di nhtfng no cd the bien doi tit dang nay sang dang khac. Phat bieu nay dtfqc goi Id dinh ludt bdo toan nang Itfong. ENRICHMENT: Bai dpc them In 1905, A lbert E instein (1879-1955) published his theory that the m ass of a sam ple of m atter is increased as the energy of the sam ple is increased For exam ple, a base ball in m otion has a ve ry sligh tly greater m ass than the sam e baseball at rest The difference in m ass is given by the fam ous equation E = m c? In this equation. £ is the energy of the ob|ect, m is the mass difference, and c' is a very large constant the square of the velocity of light c? = (3001,000 kilom ete rs/seco nd )? = 90,000,000,000 kilom ete rsV se con d' = (186,000 m ile s/seco n d)p = 34,600,000,000 m ilesV second' For m acroscopic bodies such as a baseball, the increase in m ass because of the added energy is so sm all that it is not m easurable It was not even discovered un-til the b e ginning of the tw entieth century. At atom ic and subatom ic levels, how ever, the c o n v e r sion of a sm all q uantity of m atter into energy is very im portant. It is the energy source of the Sun and the stars, the atom ic bomb, the hydrogen bom b, and nuclea r pow er plants. C hem istry is the study of the interaction of m atter and energy and the changes that m atter undergoes. (In nuclear reactions, tiny quantities of m atter are actually converted to relatively large q ua ntitie s of energy. See C hapter 20.) Chu diem 1.4: Chemical Symbols Because the e lem ents are the building blocks of all m aterials in the universe, we need an easy w ay to identify and refer to them For this purpose, each chem ical e le m ent is identified by an internationally used sym bol consisting of one or tw o letters The first letter of an ele m e n t's sym bol is alw ays capitalized If the sym bol has a s e c ond letter, it is a low ercase (small) letter. The sym bol is an abbreviation of the elem ent s nam e, but som e sym bo ls represent nam es in languages other than E nglish The 10 elem ents w hose sym -b ols and nam es have different first letters are listed in Table 1 4 A list of the nam es and sym bols of the first 109 elem ents, along with som e other in form ation, is p re sen te d in a table inside the back cover of this book. In that table, the elem ents are a lp ha be tize d according to their nam es, but d upli-cate entries appear u n der the initial letter of the sym bols for the elem ents in Table 1.4. The m ost im p o rta n t sym bols for beginning students to learn are given in Figure 1.5. The nam es of the elem ents indicated and their sym bols m ust be m em orized D on't bother to m em orize the num bers shown in the boxes with the e lem ents C he m ists w rite sym bols together in form ulas to identify co m p ou nd s For exam ple the letters CO re p re se n t a co m pound of carbon and oxygen Be careful to d istin gu ish the form ula CO from the elm en t cobalt The c a p ita li
' opic 1: liasic concepts t zation of letters is very im portant! Form ulas are som e-tim es w ritten w ith s u b s c rip ts to tell the relative proportions of the elem ents present. For e xam ple. F^O re p re se n ts w a ter, w hich has two atom s of hydrogen for every atom of oxygen p re sen t M ore about form ulas will be presented in Section 5.1. Snapshot Review - On tap nhanh *■ The first letter in a sym bol for an elem ent is alw ays ca p ita liz e d the second letter if any. is sm all (low ercase) *■ By the end of the first few weeks of this course, you should know the nam es and sym bols of the elem ents in Figure 1.5. A How m any d ifferent elem ents are represented in the form ula CO (CO) 7 • Mdu ttf dau tien trong ky lueu dung cho mot nguyen to ludn ludn phai dtfoc n et hoa; con mau ttf tliit hai neu co thi viet bang chit thtfdng. • Vao cuoi ludn dau tien cua khoa hoc, ban nen biet ten va ky hieu cua car nguyen to trong hinh 1.5. A. Co bao nliieu nguyen to dtfoc trinh bay trong cong thtfc Co /C O I f Table 1.4 E lem ents W h o se N am es and S ym bols Begin with D ifferent Letters N am e S ym bol A n tim o n y Sb Gold Au Iron Fe Lead I’ b M ercury Mg Potassium K S ilv e r Ag Sodium Na T in Sn T ungsten W Chu thich tu" - cum tC/ va hifofng dan dpc hieu - sym bol: ky hieu - form ulas: cong thtfc Ky hieu hoa hpc Bdi vi cac nguyen to la cdc khoi cau true cua tat ca cdc rat lieu trong vii tru nen cluing ta can co mot each thtfc de dang de nlidn biet co tham khuo chung Vi mur du h nay md moi nguyen to hoa hoc dtfqc nhan biet bdi moi ky hieu dtfoc dung phd Lien tren the gidi gom mot hoqc hai ky tit. Ky lueu dau tien cua mot nguyen to ludn ludn dtfqc viet being chi? hoa. Neu ky lueu co hai mdu tit, thi no phai dtfqc viet bring d id thuijng Ky lueu Id chu a c ! hit cua ten nguyen to, tuy nhien, mot vdi ky lueu phai Lieu th: tin
Topic 1: Basic concepts theo ngon ngd khac vdi tieng Anh. 10 nguyen to co ky hieu vd ten cua no co cd mau ttf ddu tiin khac nhau dtfac liet ke trong bang 1.4. M ot danh sdch ten vd ky hieu cua 109 nguyen to ddu tien cung vdi mot vdi thong tin khac dtfac trinh bdy trong bang ndm d cuoi sdch ndy. Trong bang do, cdc nguyen to dtfoc sdp xep theo thii ttf a, b, c bang chit cat tin cua chung, nhtfng cdc hang muc gap doi thi xuat hien ben dtfdi mdu ttf ban dau cua ky hieu ddnh cho nguyen to do trong bang 4. K y hieu quan trong nhat ddnh cho sinh vien mdi bdt ddu se dtfac trinh bdy trong h in h 1.5 ten cua cdc nguyen to dtfac chi dinh vd ky hieu cua chung cung phai dtfac ghi nhd. DiCng bdn tdm de nhd tat cd nhilng con so dtfac trinh bdy trong cdc 6 cung vdi cdc nguyen to. Cdc nhd hoa hoc viet cdc ky hieu cung vdi cong thilc de nhan biet cdc hap chat. Vi du cdc mdu ttf CO bieu thi mot hap chat carbon vd oxy. Phai can than de phdn biet cong thilc CO vdi ky hieu Co, von bieu thi nguyen to cobalt. ChU viet hoa cua cdc mdu ttf cung rat quan trong. Cdc cong thilc doi khi dtfac viet cung vdi cdc chi so tren de bao cho biet ty le ttfang doi cua cdc nguyen to dang co. Vi du, H f i bieu thi ntfdc, co hai nguyen tit hydro ilng vdi moi mot nguyen til oxy. Co nhieu cong thilc dtfac trinh bdy trong phdn 5.1. Chu diem 1.5: The Periodic Table In S ection 1.2, you learned a few of the properties of su lfu r and of iron. Do you have to learn the p ro pe rtie s of all 100 or so elem ents individually, or are there som e w ays to ease that burden? For over 150 years, chem ists have arranged the e lem ents in groups w ith sim ila r chem ical characteristics, w hich m akes it easier to learn th e ir p ro p erties. This gro up ing of the elem ents has been refined to a high degree, and the m od ern periodic tab le is the result. A full periodic table is show n inside the fron t co ve r of this book. The e le m e n ts num bered 104 and up in that table have only rece ntly been produced and in such infinitely sm all quantities that their chem ical p roperties are un m easured. T he refo re , we w ill alm ost totally ignore them in the rem ain de r of this book. W e w ill e xp lo re se ve ra l uses for the p eriodic table in this section, as w ell as a n um ber of te rm s used w ith it. This table w ill be used e xten sively th ro u g h -o u t the rest of this course, and in su bse qu en t chem istry courses. All the e le m e n ts in any horizontal row of the periodic table are said to be in the sam e period. T he re are seven periods, the first consisting of ju s t two e le -m e nts. The second and third p erio d s contain 8 elem ents each, and the next tw o contain 18 e le m ents each. T he sixth period has 32 elem ents (including 14 inner tran sition e lem ents n um bered 57 th ro u g h 71, located at the bottom of the table), and the last period is not yet co m plete. The periods are conve ntio na lly num -bered w ith the A rabic num erals 1 through 7. The e le m e n ts in any ve rtica l colum n in the periodic table are in the sam e group, or fam ily. T he y have sim ila r chem ical properties, which change g ra du ally from each one to the one b e lo w it; in som e groups, the elem ents are v e ry s im ila r. T he g ro up s have been given tw o sets of group num bers. The classical group n um be rs are R om an num erals follo w ed by a letter A or B. These are more useful for b eg in nin g stu de nts in learning abo ut a tom ic structure and bonding. The elem ents in tw o g roups having the sam e n um be r have som e chem ical sim ilarities, especially in the fo rm u la s of som e of th eir co m p ou nd s. A ch em ica l form ula (Section 5.1) show s the ratio of atom s of each of its e le m e n ts to e ve ry other elem ent. For exam ple, w ater, H ,0 . has tw o h ydro-gen 19