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12 NAMES OF ACIDS, BASES, AND SALTS

12 NAMES OF ACIDS, BASES, AND SALTS

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Table 6.7 Names of the Oxyacids of Chlorine



Acid formula



Acid name1



Anion name1,2



HClO4

HClO3

HClO2

HClO



Perchloric acid

Chloric acid

Chlorous acid

Hypochlorous acid



Perchlorate

Chlorate

Chlorite

Hypochlorite



1

Italicized letters are used with the names only to emphasize the prefixes and suffixes.

+

2 Names of anions, such as ClO ion from the acid.

4 formed by removal of H



Bases

Bases that contain hydroxide ion are named very simply by the rules of nomenclature for ionic compounds. The name consists of the name of the metal followed

by hydroxide. As examples, LiOH is lithium hydroxide, KOH is potassium

hydroxide, and Mg(OH)2 is magnesium hydroxide.



Salts

Salts are named according to the name of the cation followed by the name of the

anion. The names of the more important ions are listed in Table 6.8. One important

+

cation, ammonium ion, NH4 , and a number of anions are polyatomic ions, meaning

that they consist of 2 or more atoms per ion. Table 6.8 includes some polyatomic

ions. Note that most polyatomic ions contain oxygen as one of the elements.

As illustrated in Table 6.8, the names of anions are based upon the names of the

+

acids from which they are formed by removal of H ions. A “hydro -ic” acid

yields an “-ide” anion and, therefore, an “-ide” salt. For example, hydrochloric

acid reacts with a base to give a chloride salt. An “-ic” acid yields an “-ate” salt;

for example, calcium sulfate is the salt that results from a reaction of sulfuric acid

with calcium hydroxide. The anion contained in an “-ous” acid is designated by the

suffix “-ite” in a salt; sulfurous acid, H2SO3 reacts with NaOH to give the salt

Na2SO3 sodium sulfite. A “per -ic” acid, such as perchloric acid, reacts with a

base, such as NaOH, to give a “per -ate” salt, for example, sodium perchlorate,

NaClO4. A “hypo -ous” acid, such as hypochlorous acid, reacts with a base, KOH,

for example, to give a “hypo -ite” salt, such as potassium hypochlorite, KClO.

Some additional examples are illustrated by the following reactions:

2HClO4 + Zn(OH)2







2HNO3 + Cu(OH)2







HNO2 + KOH →



KNO2 + H2O



(6.12.3)



2HClO + Ca(OH)2







(6.12.4)



perchloric acid

nitric acid



nitrous acid



hypochlorous acid



© 2001 CRC Press LLC



Zn(ClO 4)2 + 2H2O



(6.12.1)



Cu(NO3)2 + 2H2O



(6.12.2)



zinc perchlorate



copper(II) nitrate



potassium nitrite



Ca(ClO)2 + 2H2O



calcium hypochlorite



Table 6.8 Some Important Ions



+1 charge



+2 charge



+3 charge



H+,

hydrogen



Mg2+,

Al3+,

magnesium aluminum



Li+,

lithium



Ca2+,

calcium



Fe3+,

2

iron(III)



Na+,

sodium



Ba2+,

barium



Cr3+,

chromium(III)



K+,

Fe2+,

potassium iron (II)

NH4+,

Zn2+,

ammonium zinc

Cu+,

Cu2+,

1

copper (I) copper(II)2

Ag+,

silver



Cr2+,

chromium(II)

Pb2+,

lead(II)1

Hg2+,

mercury(II)2

Sn2+,

tin(II)2



-1 charge



-2 charge



-3 charge



H- ,

hydride

F -,



O2-,

oxide

S2-,



N3nitride

PO 3-



fluoride

Cl-,



sulfide

SO 2-,



phosphate



chloride

Br-,



sulfate

SO 2-,



bromide

I-,



sulfite

CO 2-,



iodide



carbonate

CrO 2, -



4



4



3



3



C2H3O2-,

acetate

OH-,



chromate

Cr O 2-,



hydroxide

CN-,



dichromate

O 2-,



cyanide

NO -,



peroxide

HPO42-,

monohydrogen phosphate



3



nitrate

H PO -,

2



4



2



7



2



4



dihydrogen phosphate

HCO -,

3



hydrogen carbonate3

HSO -,

4



hydrogen sulfate3

MnO ,

4



permanganate

1



These metals can also exist as ions with a higher charge and may also be designated by their

Latin names with an -ous ending as follows: Cu+ , cuprous; Fe2+ , ferrous; Cr2+ , chromous;

Pb2+ , plumbous; Mn2+ , manganous; Sn2+ , stannous.



2



These metals can also exist as ions with a lower charge and may also be designated by their

Latin names with an -ic ending as follows: Cu2+ , cupric; Hg2+ , mercuric; Fe3+ , ferric; Cr3+ ,

chromic.

3 The ions HCO - and HSO - are known as bicarbonate and bisulfate, respectively.

3



4



© 2001 CRC Press LLC



Using the information given in Table 6.8, it is possible to figure out the formulas

and give the names of a very large number of ionic compounds. To do that, simply

observe the following steps:

1. Choose the cation and the anion of the compound. The name of the

compound is simply the name of the cation followed by the name of the

3+

2anion. For example, when Fe is the cation and SO4 is the anion; the

name of the ionic compound is iron(III) sulfate.

2.Choose subscripts to place after the cation and anion in the chemical formula of the compound such that multiplying the subscript of the cation

times the charge of the cation gives a number equal in magnitude and

opposite in sign from that of the product of the anion’s subscript times the

3+

anion’s charge. In the example of iron(III) sulfate, a subscript of 2 for Fe

2

gives 2 × (3+) = 6+, and a subscript of 3 for SO4 - gives 2 × (3-) = 6-,

thereby meeting the condition for a neutral compound.

3. Write the compound formula. If the subscript after any polyatomic ion is

greater than 1, put the formula of the ion in parentheses to show that the

subscript applies to all the atoms in the ion. Omit the charges on the ions

because they make the compound formula too cluttered. In the example

under consideration, the formula of iron(III) sulfate is Fe2(SO 4)3.

Exercise: Match each cation in the left column below with each anion in the right

column and give the formulas and names of each of the resulting ionic compounds.

+



(a) Na

2+

(b) Ca

3+

(c) Al



(1) Br(2) CO32(3) PO43-



Answers: a-1, NaBr, sodium bromide; a-2, Na2CO3, sodium carbonate; a-3,

Na3PO4, sodium phosphate; b-1, CaBr2, calcium bromide; b-2, CaCO3, calcium

carbonate; b-3, Ca3(PO 4)2, calcium phosphate; c-1, AlBr3, aluminum bromide; c-2,

A12(CO3)3, aluminum carbonate; c-3, AlPO4, aluminum phosphate.

The names and formulas of ionic compounds that contain hydrogen in the name

and formula of the anion are handled just like any other ionic compound. Therefore,

NaHCO3 is sodium hydrogen carbonate, Ca(H2PO4)2 is calcium dihydrogen phosphate, and K2HPO4 is sodium monohydrogen phosphate. The acetate ion, C2H3O2

also contains hydrogen, but, as noted previously, its hydrogen is covalently bonded

to a C atom, as shown by the structure

H O

H C C O

H



Acetate anion with covalently bound,

nonionizable hydrogens



and cannot form H+ ions, whereas the anions listed with hydrogen in their names can

produce H+ ion when dissolved in water.



© 2001 CRC Press LLC



CHAPTER SUMMARY

The chapter summary below is presented in a programmed format to review the

main points covered in this chapter. It is used most effectively by filling in the

blanks, referring back to the chapter as necessary. The correct answers are given at

the end of the summary.

1



ion is produced by acids and 2



by bases. A neutralization reaction

is

. Hydrogen ion, H +, in water is bonded

4

and is often represented as 5

. A base is a

to

substance that accepts H+ and produces hydroxide ion. Although NH3 does not

contain hydroxide ions, it undergoes the reaction 6

to produce OH- in water. The two products produced whenever an acid and a base

react together are 7

. A salt is made up of 8

. An amphoteric substance is one that

9

. In

water, a metal ion is bonded to 10

in a form known as a 11

. In terms of acid–base

. In water solution sodium

behavior, some metal ions act as 12

carbonate acts as a 13

and undergoes the reaction14

. Salts that act as acids react with 15

. Pure water conducts electricity 16

,a

solution of acetic acid conducts electricity 17

, and a solution of

HCl conducts electricity 18

.These differences are due to

differences in concentrations of 19

in the water. Materials that conduct

electricity in water are called 20

. Materials that do

not form ions in water are called 21

. The reaction

3



CH3CO2H → CH3CO2- + H+



(6.4.1)



may be classified as 22

or 23

and when the acetic acid molecule comes apart, it is said to 24

.A

base that is completely dissociated in water is called a 25

and an acid that is only slightly dissociated is called a 26

. At high

concentrations the percentage of dissociation of a weak acid is 27

than at lower concentrations. Buffers are 28

. A buffer can be made from a mixture of a

weak base and 29

. The reaction that results

in the production of very low concentrations of ions in even pure water is 30

and the relationship between the concentrations

of these ions in water is 31

. In absolutely pure water the

value of [H+] is exactly 32

, the pH is 33

, so that the solution is said

to be 34

. Acidic solutions have pH values of 35

and

basic solutions have pH values of 36

. In a general sense

solution equilibrium deals with the extent to which reversible acid-base, solubilization (precipitation), complexation, or oxidation-reduction reactions 37

. As an example of acid-base equilibrium



© 2001 CRC Press LLC



the reaction for the ionization of acetic acid, HAc, is 38

for which the acid dissociation constant is 39

ways to prepare acids are 40



. Some



.

Some ways to prepare bases are



41



.

The reaction of an ion with water such as

PO43- + H2O → HPO42- + OHis an example of a 42

. The most obvious way

to prepare a salt is by 43

. Active

metals react with acids to produce 44

. Other

than reacting with acids, some metals react with 45

. If the anion

in a salt can form a volatile acid, a new salt can be formed by 46

. Some metals will displace other metals from a salt. If magnesium, a

highly reactive metal is added to a solution of copper sulfate, the reaction that occurs

. NaHSO4, which has an ionizable

is 47

hydrogen, is an example of 48

, whereas Ca5OH(PO4)3 is an

example of 49

. The water in CuSO4 •5H2O is called 50

. The names of HClO4, HClO3, HClO2, and HClO are,

respectively, 51

.

The names of NaClO4, NaClO3, NaClO2, and NaClO are, respectively, 52

.

The name of a base containing a metal consists of 53

. As examples, LiOH is lithium hydroxide, KOH is

potassium hydroxide, and Mg(OH)2 is magnesium hydroxide. The name of a salt is

54

. The names

of the ions Ca2+, Fe3+, H-, SO32-, and C2H3O2- are, respectively, 55

.

In writing the formulas of ionic compounds, choose subscripts to place after the

cation and anion in the chemical formula of the compound such that multiplying the

subscript of the cation times the charge of the cation gives a number 56

and opposite in sign from that of the product of 57

.



© 2001 CRC Press LLC



Answers to Chapter Summary

1. H+

2. OH3. H+ + OH- → H2O

4. water molecules

5. hydronium ion, H3O+

6. NH3 + H2O → NH4+ + OH7. water and a salt

8. a cation (other than H+) and an anion (other than OH-)

9. can act as either an acid or a base

10. water molecules

11. hydrated ion

12. acids

13. base

14. 2Na+ + CO32- + H2O → Na+ + HCO3- + Na+ + OH15. hydroxide ions

16. not at all

17. poorly

18. very well

19. ions

20. electrolytes

21. nonelectrolytes

22. ionization

23. dissociation

24. dissociate

25. strong base

26. weak acid

27. lower

28. solutions that resist changes in H+ concentration

29. a salt of the base

30. H2O → H+ + OH31. [H+][OH-] = 1.00 × 10 -14 = Kw

32. 1 × 10 -7 mole/L

33. 7.00

34. neutral

35. less than 7

36. greater than 7

37. proceed in a forward or backward direction

38. HAc ←→ H+ + Ac+

39. [H ][ Ac ] = K = 1.75 x 10-5

[HAc]

40. reaction of hydrogen with a nonmetal, reaction of a nonmetal directly with

water, reaction of a nonmetal oxide with water, production of volatile acids

by reaction of salts of the acids with nonvolatile acids

41. reaction of active metals directly with water, reaction of metal oxides with



© 2001 CRC Press LLC



water, reaction of a basic compound that does not itself contain hydroxide with

water

42. hydrolysis

43. reaction of an acid with a base

44. a salt and hydrogen gas

45. strong bases

46. adding a nonvolatile acid

47. Mg(s) + CuSO4(aq) → Cu(s) + MgSO4(aq)

48. an acid salt

49. a basic salt

50. water of hydration

51. perchloric acid, chloric acid, chlorous acid, and hypochlorous acid

52. sodium perchlorate, sodium chlorate, sodium chlorite, and sodium hypochlorite

53. the name of the metal followed by hydroxide

54.the name of the cation followed by the name of the anion

55. calcium, iron(III), hydride, sulfite, and acetate

56. equal in magnitude

57. the anion’s subscript times the anion’s charge



QUESTIONS AND PROBLEMS

1. Give the neutralization reaction for each of the acids in the left column reacting

with each of the bases in the right column, below:

(1) Hydrocyanic acid

(2) Acetic acid

(3) Phosphoric acid



(a) Ammonia

(b) Sodium hydroxide

(c) Calcium hydroxide



2. Methylamine is an organic amine, formula H3C-NH2, that acts as a weak base in

water. By analogy with ammonia, suggest how it might act as a base.

3. In a 1 molar solution of acetic acid (containing 1 mol of acetic acid per liter of

solution) only about 0.5% of the acid is ionized to produce an acetate ion and a

hydrogen ion. Calculate the number of moles of H+ in a liter of such a solution.

4. What does H3O+ represent in water?

5. When exactly 1 mole of NaOH reacts with exactly 1 mole of H2SO4, the product

is an acid salt. Show the production of the acid salt with a chemical reaction.

6. An amphoteric substance can be viewed as one that may either accept or produce

+

an ion of H . Using that definition, explain how H2O is amphoteric.

7. Explain how Fe3+ ion dissolved in water can be viewed as an acidic hydrated ion.

8. Cyanide ion, CN-, has a strong attraction for H +. Show how this explains why

NaCN acts as a base.

9. Separate solutions containing 1 mole per liter of NH3 and 1 mole per liter of

acetic acid conduct electricity poorly, whereas when such solutions are mixed,

the resulting solution conducts well. Explain.



© 2001 CRC Press LLC



10. What characteristic of solutions of electrolytes enables them to conduct

electricity well?

11. A solution containing 6 moles of NH3 dissolved in a liter of solution would be

relatively highly concentrated. Explain why it would not be correct, however, to

describe such a solution as a “strong base” solution.

12. The dissociation of acetic acid can be represented by

CH CO H → CH CO - + H+

3



2



3



2



Explain why this reaction can be characterized as an ionization of acetic acid.

Explain on the basis of the “crowding” concept why the percentage of acetic

acid molecules dissociated is less in relatively concentrated solutions of the acid.

13. A solution containing 0.1 mole of HCl per liter of solution has a low pH of 1,

whereas a solution containing 0.1 mole of acetic acid per liter of solution has a

significantly higher pH. Explain.

14. Explain why a solution containing both NH3 and NH4Cl acts as a buffer. In so

+

+

doing, consider reactions of NH3, NH 4 ion, H ion, OH- ion, and H2O.

2

15. NaH2PO4 and Na 2HPO4 dissolved in water produce H2PO4- and HPO4 - ions,

+

respectively. Show by reactions of these ions with H and OH ions why a solution consisting of a mixture of both NaH2PO4 and Na 2HPO4 dissolved in water

acts as a buffer.

16. What is the expression and value for Kw? What is the reaction upon which this

expression is based?

17. On the basis of pH, distinguish among acidic, basic, and neutral solutions.

18. Give the pH values corresponding to each of the following values of [H+]:

(a) 1.00 × 10 -4 mol/L, (b) 1.00 × 10 -8 mol/L, (c) 5.63 × 10 -9 mol/L, (d) 3.67 ×

10-6 mol/L.

19. Why does solution equilibrium deal only with reversible reactions?

20. Write an equilibrium constant expression for the reaction

CO32- + H2O ←→ HCO 3- + OH21. Calculate [H+] in a solution of carbon dioxide in which [CO 2(aq)] is 3.25 × 10 4

moles/liter.

22. Cl2 and F2 are both halogens. Suggest acids that might be formed from the

reaction of F 2 with H2 and with H2O.

23. Suggest the acid that might be formed by reacting S with H2.

24. Suggest the acid or base that might be formed by the reaction of each of the following oxides with water: (a) N2O3, (b) CO2, (c) SO3, (d) Na2O, (e) CaO, (f)

Cl2O.

25. Knowing that H2SO4 is a non-volatile acid, suggest the acid that might be

formed by the reaction of H2SO4 with water.



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26. Acetic acid is a carboxylic acid. Formic acid is the lowest carboxylic acid, and it

contains only 1 C atom per molecule. What is its formula?

27. A base can be prepared by the reaction of calcium metal with hot water. Give the

reaction and the name of the base product.

28. A base can be prepared by the reaction of sodium oxide with water. Give the

reaction and the name of the base product.

29. Give the reactions by which the following act as bases in water: (a) NH3, (b)

Na2CO3, (c) Na3PO4, and dimethylamine, (CH3)2NH.

30. Choosing from the reagents H2SO4, HCl, Mg(OH)2, and LiOH give reactions

that illustrate “the most straightforward” means of preparing salts.

31. Choosing from the reagents NaOH, HCl, , CaO, Mg, F2 and Al give reactions

that illustrate the preparation of salts by (a) reaction of a metal and a nonmetal

that will react directly to make a salt, (b) reaction of a metal with acid, (c)

reaction of a metal with strong base, (d) reaction of a salt with a nonvolatile acid,

(e) cementation.

32. Describe what is meant by an acid salt.

33. Describe what is meant by a basic salt.

34. Explain how sodium carbonate decahydrate illustrates water of hydration. Why

is it less hazardous to skin than is anhydrous sodium carbonate? Illustrate with a

chemical reaction why it is also a basic salt.

35. Give the names of each of the following acids: (a) HBr, (b) HCN, (c) HClO, (d)

HClO2, (e) HClO3, (f) HClO4, (g) HNO2.

36. Give the names of (a) LiOH, (b) Ca(OH)2, and (c) Al(OH)3.

37. Give the names of (a) MgSO3, (b) NaClO, (c) Ca(ClO4)2, (d) KNO3, (d)

Ca(NO2)2

38. Match each cation in the left column below with each anion in the right column

and give the formulas and names of each of the resulting ionic compounds.

(a) Li+

(b) Ca2+

(c) Fe3+



(1) CN(2) SO32(3) NO3-



39. What color is litmus in (A) acid and (B) base?

40. Give the formulas of each of the following:

Magnesium acetate

Calcium monohydrogen phosphate

Aluminum sulfate

Calcium hypochlorite



© 2001 CRC Press LLC



41. Using Lewis (electron-dot) structures, show the reaction between hydronium ion

and hydroxide ion.

42. A common error in speaking the chemical language is to confuse acidic

(pronounced uh-sid-ik) with acetic (pronounced uh-seat-ik). What is the correct

meaning of each of these terms? What is the difference between ammonia and

ammonium?

43. The following is a list that contains the names of three cations and three anions:

hypochlorite, hydrogen, sodium, sulfate, calcium, nitrate. List the three cations.

List the three anions. Give the formulas of nine compounds that can be made by

various combinations of these.

44. Write a chemical reaction in which NaHCO 3 acts as an acid. Write another in

which it acts as a base, remembering that if H2CO3 is produced in solution it

largely goes to carbon dioxide gas and water.

45. Write the Lewis structure of the hydronium ion, H3O+.

46. Explain by chemical reactions how a mixture of NaHCO3 and Na 2CO3 in water

would act as a buffer.

47. A solid known to be either NaCl or Na2SO4 was moistened with concentrated

H2SO4 and heated, giving off a gas that turned moist blue litmus paper red. What

was the solid?

48. Formulas of some chemical compounds are given in the lefthand column. Match

the formula of each compound with its correct name in the righthand column.

CaO

SiO2

K2S

AlCl3

NO2

N2O5

NaI

KBr

MgF2

CaF2



Potassium sulfide

Dinitrogen pentoxide

Nitrogen dioxide

Silicon dioxide

Potassium bromide

Sodium iodide

Calcium oxide

Magnesium fluoride

Calcium fluoride

Aluminum chloride



49. Match the names in the right column with the formulas in the left column.

Na2CO3

CaSO3

Al(OH) 3

CaSO4

NaNO 2

Ca 3(PO 4)2

NaNO 3

Ca(ClO)2

KClO4



© 2001 CRC Press LLC



Calcium sulfate

Potassium perchlorate

Sodium carbonate

Calcium phosphate

Aluminum hydroxide

Calcium sulfite

Calcium hypochlorite

Sodium nitrate

Sodium nitrite



50. Match the names in the right column with the formulas in the left column.

K2HPO4

KHCO3

NaHSO4

KH2PO4

NaHC8H4O4

NaHC2O4



Sodium hydrogen sulfate

Sodium hydrogen oxalate

Dipotassium hydrogen phosphate

Sodium hydrogen phthalate

Potassium hydrogen carbonate

Potassium dihydrogen phosphate



51. Fill in each of the following blanks with the number corresponding to the

meaning of each of the prefixes. The first one is done for you as an example.

tetra

penta



4



mono



octa



deca



di



hepta



tri



nona



sexa



52. Give the correct name to each of the following compounds. The first one is done

for you as an example.

N2O5 Dinitrogen pentoxide

NO2

NO



N2O4

N2O3

N2O



53. Iron in a compound can also be designated as ferrous or ferric. Similarly copper

(Cu) may be called cuprous or cupric. Tin (Sn) may be called stannous or

stannic. Name each of the following compounds with two acceptable names. The

first one is done for you as an example.

FeCl2 ferrous chloride

FeCl3

CuCl

CuCl 2

SnCl2

SnCl4



or iron (II) chloride

or

or

or

or

or



54. Dry CaSO4 absorbs enough water to yield a product with a specific number or

waters of hydration. Exactly 136 g. of CaSO4 exposed to humid air gained

enough water to weigh exactly 172 g. What is the formula of the product with

the waters of hydration?

55. In each of the following chemical reactions fill in the formula of the missing

compound. The rest of the chemical equation is balanced.

2 N2 + 3 O2 →



(nitrogen trioxide)



KOH + SO2 →



(potassium hydrogen sulfite)

(potassium dihydrogen phosphate)



KOH + H3PO4 →



56. Give one or two examples of compounds in which each of the following prefixes

or suffixes is used in the compound name.

-ic

-ide



acetic acid



© 2001 CRC Press LLC



hydrochloric acid



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