Page 108 - Theory and Problems of BEGINNING CHEMISTRY

CHAP. 6] INORGANIC NOMENCLATURE 97

−
2+
−
3−
6.20. Name the following ions: (a)Pb ,(b)IO 3 ,(c)IO 4 , and (d)N .
Ans. (a) Lead(II) ion (b) Iodate ion (c) Periodate ion (d) Nitride ion
6.21. Name the following ions: (a)PO 3 3− ,(b)S , and (c)SO 4 2− .
2−
Ans. (a) Phosphite ion (b) Sulfide ion (c) Sulfate ion
6.22. Write formulas for each of the following compounds: (a) sodium chloride, (b) sodium chlorate, (c) sodium
chlorite, (d) sodium hypochlorite, and (e) sodium perchlorate.
Ans. (a) NaCl (b) NaClO 3 (c) NaClO 2 (d) NaClO (e) NaClO 4

6.23. What is the difference between SO 3 and SO 3 2− ?
Ans. The first is a compound, sulfur trioxide; the second is an ion, the sulfite ion. The sulfite ion has two extra
electrons, as shown by the 2− charge.

6.24. (a) Write the formula for calcium sulfide, calcium sulfite, and calcium sulfate. (b) How many elements
are implied in the compound by the -ide ending? by the -ite ending? by the -ate ending? (c) Name a
particular element that is implied by the -ate ending.
Ans. (a) CaS, CaSO 3 , and CaSO 4 .
(b) -ide: at least two (a monatomic anion); -ite and -ate: at least three.
(c) There is oxygen (plus another element) in the anion.

6.25. Name the following compounds: (a) CrCl 2 ,(b) CrCl 3 ,(c) CrO, (d)Cr 2 O 3 , and (e) CrPO 4 .
Ans. (a) Chromium(II) chloride (b) Chromium(III) chloride (c) Chromium(II) oxide (d) Chromium(III)
oxide (e) Chromium(III) phosphate
6.26. Write formulas for the following compounds: (a) sodium chloride, (b) sodium sulfate, and (c) sodium
phosphate.
Ans. (a) NaCl (b)Na 2 SO 4 (c)Na 3 PO 4
The only indication that there are one, two, and three sodium ions in the compound lies in the knowledge of
the charges on the ions.
6.27. Write formulas for the following compounds: (a) ammonium chloride, (b) ammonium sulfide, and
(c) ammonium phosphate.
Ans. (a)NH 4 Cl (b) (NH 4 ) 2 S(c) (NH 4 ) 3 PO 4
Note that the last two formulas require parentheses around the ammonium ion, but that the first one does not
since there is only one ammonium ion per formula unit.
6.28. Name the following compounds: (a)Ca 3 (PO 4 ) 2 and (b)Cr 2 (SO 4 ) 3 .

Ans. (a) Calcium phosphate (b) Chromium(III) sulfate. We recognize that chromium has a 3+ charge in this
compound because two chromium ions are needed to balance three sulfate ions, each of which has a
2− charge.

6.29. Fill in the table with the formula of the compound whose cation is named at the left and whose anion is
named at the column head.
Chloride Sulfate Phosphate Hydroxide

Ammonium
Lithium
Lead(II)
Vanadium(III)