ÃÐÀÌÌÀÒÈÊÀ: Ôîðìû í óïîòðåáëåíèå ñîñëàãàòåëüíîãî íàêëîíåíèÿ.
Section I
Ex. 1. Pronounce the following words:
| Ñ + 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 |
| ñ | [k] | become, active, compose, occur, direct, combine, compound, electrode, application, react, prospect, collect, nitric, cold, according, effect, can, zinc, consider, picture |
| ci | 1Ë | 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:
îñíîâà ñëîâà + -ate [cit] [it] -» ñóùåñòâèòåëüíîå sulphate, filtrate, precipitate, nitrate, carbonate
-» [it] ïðèëàãàòåëüíîå accuratc, immediate, appropriate
-> [eit] ãëàãîë operate, separate, evaporate, precipitate, investigate, correlate, dissociate, formulate
îñíîâà ñëîâà + -ó —» ïðèëàãàòåëüíîå watery, healthy, ordinary, necessary, spongy
îñíîâà ñëîâà + -able, -ible —> ïðèëàãàòåëüíîå (ñî çíà÷åíèåì âîçìîæíîñòè)
[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)3 is precipitated from an indium salt solution. 6. When KOH was added to an indium salt solution, a precipitate of In(OH)3 was formed.
Text 10 A
Indium
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)3 and 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)3 was 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