Nomenclature of acids

Nonoxygenous acids

These acids are without oxygen.

For example, HCl – hydrogen is expressed by the prefix hydro- and the name of the main element ending with the suffix –ic because they are only in one form (hydrochloric acid), or the same rule applies as for binary non-metallic compounds (hydrogen chloride). Likewise, HF can either be called hydrofluoric acid or hydrogen fluoride.

Oxoacids

They contain hydrogen, an element forming their name, and oxygen.

This is the case of the older and rather unfortunate way of naming substances, which was briefly mentioned in the chapter about naming binary compounds containing a metal. As you may remember, it uses the endings –ic or –ous, the former referring to a higher oxidation state and the latter to a lower one. Accordingly, H₂SO₄ is called sulphuric acid (higher oxidation state of sulphur) and H₂SO₃ sulphurous acid (lower oxidation state). The problem is that you need to know what oxidation states that element really achieves or, more precisely, which oxoacids it really forms. Unfortunately, substances are still named using this system, although the IUPAC (an organisation that sets rules for the nomenclature) is taking steps to change it.

If an element forms more than two oxoacids, the prefixes hypo- and per- are employed.

So e.g. HClO is hypochlorous acid (hypo- refers to a lower oxidation state than the one

marked with the ending –ous)

HClO₂ is chlorous acid

HClO₃ is chloric acid (-ic referring to a higher oxidation state than –ous)

HClO₄ is perchloric acid (per- meaning a higher oxidation state than an acid with

the suffix –ic at the end)

Salts of oxoacids are formed in a very similar way (using partly the older method and partly the stock system). Once you know the name of the acid, simply change its ending: –ous into –ite, and –ic into –ate.

Thus, for example, NaClO is called natrium hypochlorite (the name of the element is natrium /sodium and the name of the acid is hypochlorous, so just change its ending from –ous to –ite).

Fe(ClO₃)₂ is called iron (II) chlorate (mark the oxidation state of iron in the same way as in the stock system of binary compounds with a metal, then take the name of chloric acid (HClO₃) and change its ending from –ic to –ate).

22 Name the following compounds:

N₂O₃

CuCl₂

H₂CO₃

CaCO₃

KNO₃

Fe(OH)₃ ____________

HBrO₃

HF

KOH

23 Create formulae of the following compounds:

iron (II) oxide

hydrobromic acid

bromic acid

sulphuric acid

diphosphorus pentaoxide

carbon (mono)oxide

sulphur tetraiodide

lead (II) iodide

24 Match the chemical formulae with the correct name and the definition:

1) MgO citric acid a) it is a white crystalline solid; it is a major

chemical in the world and one of the most

damaging salts in structure conservation; the

hydrate is known as Glauber´s Salt

2) HCL acetylene b) in the lower atmosphere is an air pollutant

with harmful effects on the respiratory

systems of animals, it can burn sensitive

plants; it is a pale blue gas soluble in water

3) CaCl₂ sodium chloride c) it is used for relief of heartburn and sore

stomach ; to improve symptoms of

indigestion

4) CO₂ sodium sulphate d) it is a colourless gas which forms white

fumes ; skin contact can cause redness,

pain, severe skin burns

5) C₂H₂ trioxygen e) it is a weak organic acid and a natural

preservative; it is also used to add an

acidic, or sour taste to food and soft

drinks; it exists in a variety of fruits

6) NaCl magnesium oxide f) it is a colourless gas widely used as a

fuel; it is mainly manufactured by the

particial combustion of methane; it has

explosive character and ability to poison

7) Na₂SO₄ ethanol g) it is solid at room temperature; it can be

produced directly from limestone; as an

ingredient it is listed as a permitted food

additive in EU as E509

8) O₃ hydrogen chloride h) it is a gas at standard temperature and

pressure; it exists in Earth´s atmosphere

in this state; it is known as a part of

photosynthesis

9) C₂H₅OH calcium chloride i) it is essential for animal life in small

quantities; it can be harmful to animals

and plants in excess; it is used for food

preservation

10) C₆H₈O₇ carbon dioxide j) it is also called pure alcohol; it is

a flammable, colourless liquid, known as

an essential solvent; it is used in

medicine, food industry, etc.

25 Study mathematical terms, units, symbols.

Calculations

9 + 2 = nine plus two equals / is equal to

20 – 7 = twenty minus seven equals / is equal to

4 x 36 = four multiplied by thirty-six equals / is equal to

10 : 5 = ten divided by five equals / is equal to

= log base a of x equals / is equal to

Powers and roots

x² x squared

x³ x cubed

x⁴ x to the power (of) four / x to the four / x to the fourth (power)

x^-5 x to the power (of) minus five / x to the minus five / x to the fifth (power)

the square root of x

the cube root of x

the n^th root of x

Numbers

100 a / one hundred

101 a hundred and one and is often left out in AmE

4,938 four thousand nine hundred and thirty-eight

5,405 five thousand four hundred and five

Ordinals

1^st the first

2^nd the second

3^rd the third

24^th the twenty-fourth

Decimals

0.25 nought / zero point two five After the point, say numbers separately.

Fractions

a / one half

five halves

a / one third

two thirds

a / one quarter

a / one fifth

three sevenths

twenty-seven over two hundred Complex fractions are usually said with over.

a over b

Percentages

27 % twenty-seven per cent

Temperature

95° C ninety-five degrees Celsius/Centigrade

13° F thirteen degrees Fahrenheit

Units

mol mole

mol/dm³ a mole per cubic decimetre / AmE decimeter

ml millilitre / AmE milliliter

Symbols

( ) round brackets

[ ] square brackets

{} curly brackets

(A+B) open brackets, A plus B, close brackets / A+B in brackets

A < B A is less than B

A > B A is greater than B

A ≠ B A is not equal to B

A ≈ B A is approximately equal to B

→ give(s), lead(s) to, yield(s)

↔ forms and is formed from

A capital A

a small a

p₁V₁ = p₂V₂ small p subscript one capital V subscript one equals small p subscript two capital

V subscript two

Chemical formulae can also be read with the help of spelling:

e.g. 2 Na₂S could be read as two molecules of [en ei tu: es]

26 Read the following expressions.

25,326 58th 1.012 15,123,014 7⁶ 100°C 5,093 15.012

6 H₂O 3 H₂SO₃ 8% 2 KClO₃ → 2 KCl + 3 O₂ 14^-2

9 mol/dm³ 5 Cu (NO₃)₂

27 Read the article and do the following exercises:

a) Make collocations used in the article.

1. cell a patterns

2. marine b technologies

3. UV c field

4. solar d nanostructures

5. new e walls

6. silica f algae

7. to diffract g radiation

8. magnetic h light

9. multilayer i crystals

10. photonic j energy

1 __ 2 __ 3 __ 4 __ 5 __ 6 __ 7 __ 8 __ 9 __ 10 __

b) Fill in the missing prepositions. You can consult the article.

1. ___ a scale of around 100 nm

2. rely ___ nanoscale effects

3. seen ___ nature

4. studied ___ researchers

5. 100-200 nm ___ size

6. ___ the University of Utah ___ 2008

7. ___ any angle

8. work ____ the lab

9. made ____ crystals

10. coated ____ a layer

c) Scan through the article and find synonyms of the following expressions:

1. effectively

2. making possible

3. cleared away

4. to have or own something

5. to manufacture

6. to start, to launch

7. actually

8. to be supposed

9. to look at carefully in order to find out something

d) Form antonyms of the following words from the article:

1. natural

2. better

3. dim

4. strong

5. useful

6. exactly

7. visible

8. commonly

9. inner

e) In the article find the words corresponding to the following definitions:

1. very simple, usually very small plants that live in or near water; they have no roots, stems

or leaves

2. the outer part of an object

3. a set of animals or plants in which the members have similar characteristics to each other

4. having an empty space inside

5. to increase the strength of something

f) Form other parts of speech from the words used in the article.

1. are assumed noun:

2. are discovering noun:

3. occurs noun:

4. developing noun:

5. diffract noun:

6. a damage verb:

7. applications verb:

8. reflectance verb:

9. a cell adjective:

10. nature adjective:

g) Look at the phrases below. With your partner, try to recall exactly how these were used

in the article.

1. drug delivery tools

2. the hydrophobicity of surfaces

3. a self-cleaning plant

4. nano-sized photonic crystals

5. the wavelength of UV radiation

h) Summarize the article.

28 Unscramble the nouns below and explain their meaning in English.

1. cipipretant _______________ 3. rivadetive _________________

2. antcatre __________________ 4. mopocnent _________________

29 Explain the jokes about chemists and chemistry.

question: Why are chemists good at solving problems?

answer: They have all the solutions.

question: If H-two-O is the formula for water, what is the formula for ice?

answer: H-two-O cubed.

teacher: “What is the formula for water?”

student: “H,I,J,K,L,M,N,O”

teacher: “That´s not what I taught you! ”

student: “But you said the formula for water was H – to – O. ”

A chemist walks into a pharmacy and asks the pharmacist:

“Do you have any acetylsalicylic acid?”

“Do you mean aspirin?” asked the pharmacist.

“That´s it, I can never remember the word.” answered the chemist.

teacher: “What does HNO₃ signify?”

student: “Well, …ah, … I´ve got it right on the tip of my tongue.”

teacher: “Well, you had better spit it out.”

Why did the white bear dissolve in water?

Because it was polar.

GRAMMAR LINKS

30 Study two sections of the Grammar File - Passive voice and Relative clauses.

UNIT 3

Date: 2015-01-12; view: 1833