Section 4.2 Classwork
Answers
Practice Problems and Review
Practice Problem – Exercise 4.7 (p.111)
Name each of the following compounds.
a. Ca(OH)2 - calcium hydroxide
b. Na3PO4 – sodium phosphate
c. KMnO4 –potassium permanganate
d. (NH4)2Cr2O7 – ammonium dichromate
e. Co(ClO4)2 – cobalt(II) perchlorate
f. KClO3 – potassium chlorate
g. Cu(NO2)2 – copper(II) nitrite
Practice Problem – Exercise 4.8 (p.112)
Name the following compounds
a. NaHCO3 – sodium bicarbonate
b. BaSO4 – barium sulfate
c. CsClO4 – cesium perchlorate
d. BrF5 – bromine pentafluoride
e. NaBr – sodium bromide
f. KOCl(KClO) – potassium hypochlorite
g. Zn3(PO4)2 – zinc phosphate
Practice Problem – Exercise 4.9 (p.115)
Write the formula for each of the following compounds.
a. ammonium sulfate – (NH4)2SO4
b. vanadium(V) fluoride – VF5
c. disulfur dichloride – S2Cl2
d. rubidium peroxide – Rb2O2
e. aluminum oxide – Al2O3
Section 4.2 Review Questions (p. 116)
1. What patterns can you see in Table 4.4 that reduce the number of polyatomic
ions you need to memorize?
Answers vary – group by element other than oxygen or hydrogen.
2. How is naming a compound that contains a polyatomic ion different from
naming a binary compound?
The naming is the same… name the cation, then name the anion.
3. How can you tell how many of w\each element or polyatomic ion to put in a
compound from the formula?
Look at the subscript.
4. How can you tell whether a compound should be named as an acid?
The formula starts with H and it has (aq) as a subscript.
5. Name the following
a. HClO4 -- perchloric acid
b. HNO2 – nitrous acid
c. HBr – hydrobromic acid
d. H2SO4 – sulfuric acid
6. Copy and complete the following table.
Name
Sodium nitrate
Potassium sulfite
Sodium bicarbonate
Aluminum sulfate
Potassium perchlorate
Copper(II) carbonate
Sodium acetate
Acetic acid
Copper(II) sulfate
Calcium hydroxide
Nickel(II) carbonate
Ammonium nitrate
Formula
NaNO3
K2SO3
NaHCO3
Al2(SO4)3
KClO4
CuCO3
NaC2H3O2
HC2H3O2(aq)
CuSO4
Ca(OH)2
NiCO3
NH4NO3