Lesson 10

  1. Lesson 11
  2. Lesson 12
  3. Lesson 13
  4. Lesson 14
  5. Lesson 15
  6. Lesson 16

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Section I

Ex. 1. Pronounce the following words:

+ e, i, y M place, acid, central, presence, c / ty, per cent, except, circle, cinema, centuiy, precipitate, decide, December, face, nccessary, peace, pencil, cycle, cyclic, cylinder, receive, process
[K] become, active, compose, occur, direct, combine, compound, electrode, application, react, prospect, collect, nitric, cold, according, effect, can, zinc, consider, picture
ci 1 commercial, socialist, coefficient, special, efficiency, especially, dissociate, associate, sufficient, appreciable
M calcium, glacial, society, specific, specimen, dissociation, association
ch Wl such, which, chair, change, children, each, much, rich, March, teach, choose, touch
M chemist, chemistry, chemical, characteristic, chlorine, chloride, mechanical, technical
tch W1 catch, watch, switch
ck [K] back, black, clock, hockey, quick, ticket, attack, chcck, nickcl, thick

b) laboratory [Id'borotri], curiosity [.kjoon'ositi], available [o'vcilobl], exhibit [lg'zibit], anhydrous [am'haidros], dilute [dai'lu: t], equation [l 'kweijon], hydroxide [haf droksaid], residue [' rezidju :), approximately [o'proksimoth]

Ex. 2. Read the following words and say what Russian words help to understand their meanings:

gram, laboratory, mineral, per cent, characteristic, group, oxide, combination, halide, stable, hydrate, electrode, potential, concentrate, reaction, metallic, volt, spcctral, line, analysis, method, extract, zinc, indium, material , collect, mass, cadmium, filter, filtrate, result, neutralize, basic, sulphite

Ex. 3. Pay attention to the following way of word-building:

+ -ate [cit] ??[it] - sulphate, filtrate, precipitate, nitrate, carbonate

- [It] accuratc, immediate, appropriate

-> [Eit] 䳺 operate, separate, evaporate, precipitate, investigate, correlate, dissociate, formulate

+ - - " watery, healthy, ordinary, necessary, spongy

+ -able, -ible -> ( )

[Cibl] able, stable, unstable, enable [ibl] possible, sensible

[Obi] agreeable, probable, capablc, considerable, desirable, available

Ex. 4. Give the initial forms of the following words and find their meaning in a dictionary:

attempted, applications, quantities, exhibits, places, lies, scries, extracting, ores, considered, leaving, boiled, analyses, composed, prccipitatcd, halidcs, supplies, salts, curiosities

Ex. 5. Define the meaning of the italicized words.

1. No commercial applications of indium were attempted for many years. 2. Their attempt to obtain pure indium was a success. 3. The available supply of indium at that time was only one gram. 4. Some compounds of indium were supplied for further analysis. 5. In (OH)3is precipitated from an indium salt solution. 6. When KOH was added to an indium salt solution, a precipitate of In (OH)3was formed.

Text 10 A


Indium was regarded as a laboratory curiosity for many years and no commercial applications were attempted until 1924. It would hardly be possible to think of its application, for the available supply at that time was only one gram, with no immediate prospects of more.

Indium seldom occurs in a mineral in quantities over 0.1 per cent.

Several mcUiods of extracting indium from its ores should have been considered. According to one of them, indium-bearing zinc metal was treated widi a quantity of dilute H2SO4 which would dissolve almost all the material, leaving a residue of zinc. On this residue there was collected a spongy mass composed of lead, coppcr, cadmium, tin, arsenic, iron, and indium. Nitric acid was used to dissolve die spongy mass, after which the solution was evaporated with sulphuric acid. Lead sulphate was left behind on the filter. The filtrate was treated with NHj (aq) to precipitate In (OH)3and Fc (OH)3 which were dissolved in HC1. The resulting solution was approximately neutralized and boiled with NaHS03, Which precipitated the basic sulphite, In2(S03)3-In (OH)3-SHjO. The basic sulphite was dissolved in sulphuric acid and pure In (OH)3was obtained by the addition of NH3(Aq).

Indium exhibits properties characteristic of the aluminium group.

Indium burns in air with a blue flame to form the sesquioxidc, ln:03. If it were heated in the presence of halogens or sulphur, dircct combination would take placc. In each ease indium goes to its highest oxidation state. The other halides (InX and InX2, Where X is a halogen) have been prepared, with the possible exceptions of InF and InF:. Only the halides, InX3, Arc stable in the prcscncc of water. There arc three tri-fluorides of indium, the hydrates of the compositions InF3* 3H:0 and InF3* 9H20 and the anhydrous salt, InF3. Most indium compounds arc soluble in water.

Words and Word-Combinations to Be Memorized

Acctic acid, addition, almost, aluminium, analysis, anhydrous, approximately, attempt, available, basic, boil, case, collect, compose, composition, dilute, dircct, clcctrodc, equation, evaporate, exception, exhibit, extract, filter, fluoride , halide, hardly, hydroxide, indium, laboratory, lie, mass, material, most, nitric acid, oxidation, per cent, potential, precipitate, prevent, regard, residue, salt, seldom, scries, sulphite, soluble, supply, take placc, volt

Ex. 6. Give the Russian equivalents for the following:

attempt applications, regard smth. as, hardly, be available, immediate prospects, over 1 per cent, exhibit properties, burn with a blue flame, in the prcscncc of, take placc, in cach ease, oxidation state, with the exception of, be soluble in water, in the elcctromotivc series, an clcctrodc potential, dilute acid, react with the evolution of hydrogen, together, concentrated
acid, acctic acid, according to the equation, to have some effect on smth., to dissolve almost all the material, the resulting solution

Ex. 7. Give the English equivalents for the following:

, , 1 , , , ?? , , , , , , ', ( ) , , , , , ', , ( ),

Ex. 8. Fill in the blanks with prepositions where necessary.

of, at, in, between, with, from, according to, for

1 .... many years indium was regarded as a laboratoiy curiosity. 2. There arc several methods ... extracting ... indium ... its ores. 3. ... one ... the methods ... obtaining indium, indium-bearing zinc is treated ... dilute H: S04. 4. Indium exhibits properties characteristic ... the aluminium group. 5. Indium burns ... air ... a blue flame. 6. If indium is heated ... the presence ...

halogens or sulphur, direct combination takes place. 7 each case indium

is ... its highest oxidation state. 8. Only the halides, InX3, Arc stable ... the presence ... water. 9. Most indium compounds arc soluble ... water. 10. Indium lies ... iron and tin ... the electromotive series. 11. Characteristic spectral blue lines ... indium occur ... 451.1 and 410.1 .

Ex. 9. a) Mind:


No article is used before nouns denoting some branch of science, the names of chemical elements and the word school.

1.My younger sister goes to school.

2.While at school I liked chemistry best.

3. Indiumhas an clcctrodc potential of + 0.336 volt.

b) Translate the sentences into English.

1. , , , . 2. ³ . 3. . 4. . 5. ? 6. 쳿? 7. - , . 8. , . 9. . 10. , , , , , . 11. , .

Ex. 10. Translate the sentences into Russian, paying attention to the subjunctive mood.

1. There would be no life without such elements as carbon, oxygen, hydrogen, etc. 2. It is necessary that the substanccs be pure. 3. The teacher suggested that the equation of the reaction be written on the blackboard. 4. The solution is diluted lest it be very strong. 5. They would do it oncc more if they had time. 6. The condition was made that the reaction should procccd slowly. 7. He should have told us about the new time-table. 8. She should have done it yesterday but she did not know that her results were not accuratc. 9. Heating or cooling would affect the state of water, but not its composition. 10. Dry gas would occupy less volume. 11. It would be difficult to find a more abundant element than oxygen. 12. The corrosion would procccd much more rapidly in the prcscncc of oxygen. 13. We would begin the calculation but wc have no all the ncccssary data. 14. You should have known that these arc inflammable substanccs. IS. They should have described the properties of the substanccs that were obtained. 16. It would be true to say that experiment is the foundation of chcmistry. 17. The new apparatus would have given more accurate results. 18. It is essential that water should be turned into vapour. 19.1 wish she were right. 20.1 should have asked the tcachcr but I could not come to the seminar. 21. They suggest that the experiment be started at once.

Ex. 11. Translate the sentences into English.

1. . 2. III . 3. 䳿 1203.4. ' . 5. ?? 䳺 . 6. . 7. .

Ex. 12. Make up questions to the italicized parts of the sentences.

1. Indium lies between iron and tin in the electromotive scries (2).

2. Two reactions arc possible with concentrated sulphuric acid (3).

3. Several methods of extracting indium from its ores arc possible (2).

Ex. 13. Answer the following questions:

1. What is the occurrcncc of indium in nature? 2. What properties docs indium exhibit? 3. What can you say about commercial applications of indium? 4. What kind of oxide docs indium form? 5. What compounds of indium and the halogens arc known? 6. In what way docs indium react with sulphuric acid? 7. What docs the spectral analysis show?

Scction II

. 1. 10 . , -IIII6) 71 ?

. 2. :

material, medicine, pharmaceutical, thallium, platinum, busmuth, temperature, corrosion, discomfort, patient, dentist, amalgamate, diffuse, uniform, porous, attack, diffuse

. 3. . .

1. Sometimes chemists add indium to obtain desirable (needed) properties of substances. 2. Indium forms alloys (mixtures of metals) with lead, tin, silver, gold, platinum and others. 3. Unique properties of indium enable (give the possibility) it to be used in medicine. 4. Indium alloys arc very corrosion-resistant (unaffected by corrosion). 5. Indium can be deposited on the article (Uiing) coated with zinc or cadmium.


purpose - ; jeweller} '- ; mordant - , ; dyestuff- ; braze-; insert - ; cast - ( ); limbs - ; molten - ; filling - (); conventional - ; plate- ; bake - ; chip - ; peel -

Text 9 | Lesson 11 | Fascinating Phosphorus | Modifications of Phosphorus | Lesson 12 | Chemical Symbols for Representing Compounds | Weight of 12 atom of carbon 12 | Lesson 13 | Text 13 A The History of Chemistry | Text 13 |

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