174 CHAPTER 4: Some Types of Chemical Reactions
metallic: (a) aluminum or sodium, (b) aluminum or zinc,
(c) sodium or potassium, (d) silver or sulfur.
124.Use the general metallic trend of the periodic table to pre-
dict which element in each of the following pairs is more
metallic: (a) phosphorus or sulfur, (b) francium or uranium,
(c) oxygen or sulfur, (d) selenium or chlorine.
125.Calcium phosphate is the component of human bone that
provides rigidity. Fallout from a nuclear bomb can contain
radioactive strontium-90. These two facts are closely tied
together when one considers human health. Explain.
126.Limestone consists mainly of the mineral calcite, which is
calcium carbonate. A very similar deposit called dolostone
is composed primarily of the mineral dolomite, an ionic
substance that contains carbonate ions and a mixture of
magnesium and calcium ions. (a) Is this a surprising mix-
ture of ions? Explain, based on the periodic table. (b) A
test for limestone is to apply cold dilute hydrochloric acid,
which causes the rapid formation of bubbles. What causes
these bubbles?129.When the following pairs of reactants are combined in a
beaker: (a) describe in words what the contents of the
beaker would look like before and after any reaction that
might occur, (b) use different circles for atoms, molecules,
and ions to draw a nanoscale (particulate-level) diagram of
what the contents would look like, and (c) write a chemi-
cal equation for any reactions that might occur.LiCl(aq) and AgNO 3 (aq)
NaOH(aq) and HCl(aq)
CaCO 3 (s) and HCl(aq)
Na 2 CO 3 (aq) and Ca(OH) 2 (aq)130.Explain how you could prepare barium sulfate by (a) an
acid–base reaction, (b) a precipitation reaction, and (c) a
gas-forming reaction. The materials you have to start with
are BaCO 3 , Ba(OH) 2 , Na 2 SO 4 , and H 2 SO 4.BUILDING YOUR KNOWLEDGE131.All of the following useful ammonium salts dissolve easily
in water. Suggest the appropriate aqueous acid for prepar-
ing each salt, and describe each preparation by a balanced
“complete formula” equation. (a) Ammonium chloride:
Used in medicine as an expectorant and in certain solder-
ing operations as a “flux.” (b) Ammonium nitrate: A
valuable fertilizer, but potentially explosive; as in the 1995
bombing of the Federal Building in Oklahoma City.
(c) Ammonium sulfate: A common fertilizer often recom-
mended for alkaline soils. (d) Ammonium phosphate: A
particularly valuable fertilizer providing both nitrogen and
phosphorus, essential elements for plant growth.
132.How many moles of oxygen can be obtained by the decom-
position of 10.0 grams of reactant in each of the following
reactions?
cat.
(a) 2KClO 3 (s) 888n2KCl(s)3O 2 (g)
(b) 2H 2 O 2 (aq) n2H 2 O()O 2 (g)
heat
(c) 2HgO(s) 888n2Hg()O 2 (g)
133.Magnesium oxide, marketed as tablets or as an aqueous
slurry called “milk of magnesia,” is a common commercial
antacid. What volume, in milliliters, of fresh gastric juice,
corresponding in acidity to 0.17 MHCl, could be neu-
tralized by 125 mg of magnesium oxide?MgO(s)2HCl(aq) 88nMgCl 2 (aq)H 2 O()134.What mass of Zn is needed to displace 20.6 grams of Cu
from CuSO 4 5H 2 O?The Dolomite Alps of Italy.127.Chemical equations can be interpreted on either a partic-
ulate level (atoms, molecules, ions) or a mole level (moles
of reactants and products). Write word statements to
describe the combustion of butane on a particulate level
and a mole level.2C 4 H 10 (g)13O 2 (g) 88n8CO 2 (g)10H 2 O()128.Write word statements to describe the following reaction
on a particulate level and a mole level.P 4 (s)6Cl 2 (g) 88n4PCl 3 ()