What Is Caustic Soda 1s2b4t

What is Caustic Soda? 1. 2. 3. 4. 5. 6.

caustic ['kɔːstɪk] – едкий lye [laɪ] - щёлок, крепкий щелочной раствор base [beɪs] – основание flakes [fleɪks] – хлопья pellet ['pelɪt] – гранула ready-made [ˌredɪ'meɪd] – заранее

заготовленный 7. solution [sə'luːʃən] – раствор 8. application [ˌæplɪ'keɪʃən] – применение 9. detergent [dɪ'tɜːʤənt] – моющее средство 10.soluble ['sɔljəbl] – растворимый 11.solvent ['sɔlvənt] – растворитель 12.dissolution [ˌdɪsə'luːʃən] – растворение 13.exothermic [ˌeksəu'θɜːmɪk] – экзотермический 14.amount [ə'maunt] – количество 15.acidic [ə'sɪdɪk] – кислотообразующий

16.by-product ['baɪˌprɔdʌkt] – побочный прод 17.transition [træn'zɪʃən ] metal – переходны металл 18.alkaline ['ælkəlaɪn] – щелочной 19.to pulp [pʌlp] – размягчать 20.fiber [faɪbə] – волокно 21.to bleach [bliːʧ] – отбеливать,

обесцвечивать 22.ester ['estə] – сложный эфир 23.anhydrous [æn'haɪdrəs] – безводный 24.grease [griːs] – жир 25.to etch [eʧ] – гравировать 26.to polish ['pɔlɪʃ] – шлифовать 27.to refine [rɪ'faɪn] – очищать от примесей 28.bauxite ['bɔːksaɪt]ore – алюминиевая руда 29.mud viscosity [vɪs'kɔsətɪ] – вязкость

бурового раствора 30.to eliminate [ɪ'lɪmɪneɪt] – очищать, устран

Caustic soda, also known as sodium hydroxide (NaOH) or lye, is a white inorganic metallic base, highly caustic and usually available in granules, flakes or pellets or in ready-made solutions of various strengths. As a strong chemical base, it’s used in multiple industrial applications from the manufacture of paper to detergents. Let’s have a closer look at some of its most important properties and uses. Chemical and physical properties •

Solubility: Pure caustic soda is highly soluble in water, but with a

limited solubility in alcohol and completely insoluble in non-polar solvents. Adding this compound to water must be done with extreme caution, as its dissolution is a highly exothermic reaction and a considerable amount of heat is generated. It’s essential to follow good laboratory practices to avoid accidents. •

Reaction with acids: Like all other basis, this compound reacts with acids to produce

salt and water. A good example involves the production of sodium chloride (NaCl) after reaction between hydrochloric acid(HCl) and caustic soda (NaOH). This type of reactions are commonly used in the lab. •

Reaction with oxides: Caustic soda can also react with acidic oxides, such as carbon

dioxide (CO2) and sulphur dioxide (SO2). This type of reaction is commonly used in many industrial processes to prevent the release of harmful gases into the atmosphere, converting them to safer by-products. •

Reaction with metals: Caustic soda cannot react with iron, but a few transition

metals, including aluminium, are strongly affected by this compound. •

Hydrolysis reaction: Caustic soda can undergo hydrolysis reactions with several

compounds.

Common uses and applications Caustic soda has multiple industrial uses, mostly relying on its strong alkaline properties. Possibly the most important use is in the paper manufacturing process, closely followed by detergent production. •

Chemical pulping: Sodium hydroxide is commonly used during the process of wood

pulping in the paper industry. In fact, it’s one of the key ingredients used to separate lignin [ˈlɪgnɪn] from cellulose fibers, as well as later stages of bleaching the pulp. •

Soap making and other esterification reactions: Sodium hydroxide is also the

main ingredient during the process of making soap. A similar esterification reaction, but crucially only using anhydrous sodium hydroxide, is used in the manufacture of biodiesel. •

Cleaning agent: At home, one of the most popular products to deal with a stubborn

pipe blockage is caustic soda, as it can dissolve a wide variety of products including grease and oil, as well as proteins (like in hair, for example). •

Dissolving metals: Caustic soda can be highly corrosive to certain metals, with the

production of hydrogen gas. This reaction is the basis for many processes, including etching and polishing a surface. Using the same principle, caustic soda is involved in refining bauxite ores to produce aluminium oxide, which is subsequently used to get pure aluminium metal. •

Oil industry: In a small scale, caustic soda is also used in the oil industry to increase

mud viscosity and eliminate any gas produced. Task 1. Make up word-combinations according to the text 1

to use

a

a considerable amount of heat

2 3 4 5 6 7 8 9 1

to to to to to to to to to

b c d e f g h i j

to safer by-products a closer look the pulp the release of harmful gases hydrolysis reactions in water with acid pure metal with extreme caution

0 1

to bleach

k

a surface

1 1

to dissolve

l

accidents

2 1

to polish

m

grease and oil

3 1

to get

n

have be soluble do generate avoid react prevent convert undergo

in multiple industrial applications

4 1

2

3

4

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Task 2. Translate word-combinations into English А Б

рассматривать более подробно избегать несчастных случаев -

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В

применять в различных областях

Г Д Е Ж З И

промышленности шлифовать поверхность обесцвечивать древесную массу растворять жиры и масла очищать метал от примесей делать крайне осторожно преобразовывать в более безопасные побочные

К Л М Н О

продукты предотвращать выброс токсичных газов подвергаться реакции гидролиза растворяться в воде вступать в реакцию с кислотой выделять значительное количество тепла -

Task 3. Match the beginning and the ending of the sentences 1

Caustic soda, also known as sodium hydroxide, is

a detergents.

2

a white inorganic Caustic soda is available in granules, flakes, pellets

b salt and water.

3

or in ready-made Sodium hydroxide is used in multiple industrial

c the paper industry

4

applications from the manufacture of paper to Pure caustic soda is highly soluble in water, but it

d aluminium oxide.

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completely insoluble in Sodium hydroxide reacts with acids to produce Caustic soda cannot react Sodium hydroxide is commonly used during the

e caustic soda. f metallic base. g metals.

8

process of wood pulping in An esterification reaction s used in the manufacture

h with iron.

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of One of the most popular products to deal with a

i

viscosity.

1

stubborn pipe blockage is Caustic soda can be highly corrosive to certain

j

solutions.

0 1

Caustic soda is involved in refining bauxite ores to

k non-polar solvents.

1 1

produce Caustic soda is also used in the oil industry to

l

2

increase mud

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biodiesel.

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Task 4. Match and definitions 1

base

a

a type of chemical reaction witch goes on with the liberation of heat

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solution detergent

b c

to make the surface of something smooth and shiny

4

exothermic

d

to remove impurities or unwanted elements from a

e

substance an organic compound made by replacing the hydrogen of

a class of compounds whose aqueous solutions are characterized by the ability to react with acids to form salts.

5

alkaline

an acid by an alkyl or other organic group

6 7 8 9 1

ester anhydrous grease bauxite ore pulp

f g h i j

a clay-like substance from which aluminium is obtained.

0 1

bleach

k

animal fat used or produced in cooking

1 1

refine

l

having the properties of an alkali, having a pH greater than

2 1

eliminate

m

7 to crush into a soft and shapeless mass

3 1

polish

n

containing no water

a homogeneous mixture of two or more substances

to make white or much lighter to remove completely a cleaning agent that increases the ability of water to break down greases and dirt.

4 1

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3

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8

Task 5. Match pictures and the words. bauxite ore, fiber, grease, pellet, detergent, flakes

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