Bettelheim Concepts Flashcards
(194 cards)
1
Q
Drug dosage are prescribed based on
A
Body mass and age
2
Q
Too much heat is lost and body temperature drops, this conditiob is called
A
Hypothermia
3
Q
It can caused either by high outside temperature or buly the body itself when an individual develops a high fever. Opposite of Hypothermia
A
Hyperthemia
4
Q
The high specific heat of ________ is useful in cold compresses and makes them last a long time
A
Water
5
Q
The big four elements in human body
A
Carbon,hydrogen, nitrogen,oxygen
6
Q
Trace elements
A
Chromium,cobalt,copper,flourine,iodine,iron,manganese,molybdenum,zinc
7
Q
Strengthens bones and teeths;aids in blood clotting
A
Calcium
8
Q
Present in phosphates of bones in nucleic acids(DNA and RNA) and involved in energy transfer
A
Phosphorus
9
Q
Help regulate electrical balance of body fluids; essential for nerve conduction
A
Potassium
10
Q
An essential component of proteins
A
Sulfur
11
Q
Necessary for normal growth and development
A
Chlorine
12
Q
Helps regulate electrical balance in body fluids
A
Sodium
13
Q
Helps nerve and muscle action; present in bones
A
Magnesium
14
Q
Increase effectiveness of insulin
A
Chromium
15
Q
Part of vitamin B12
A
Cobalt
16
Q
Strengthens bones;assist in enzyme activity
A
Copper
17
Q
Strengthens bones;assist in enzyme activity
A
Copper
18
Q
Reduce the incidence of dental cavities
A
Fluorine
19
Q
An essential part of thyroid hormones
A
Iodine
20
Q
An essential part of some proteins, such as hemoglobin,myoglobin,cytochromes,and FeS proteins
A
Iron
21
Q
Present in bone forming enzymes; aids in fat and carbohydrate metabolism
A
Manganese
22
Q
Helps regulate electrical balance in body fluids
A
Molybdenum and sodium
23
Q
Necessary for action of certain enzymes
A
Zinc
24
Q
Most abundant element by mass present in human body and in Earth’s crust
A
Oxygen
25
Most abundant element in human body by atom
Hydrogen
26
2nd most abundant element by mass in human body
Carbon
27
Refers to the relative amounts of the isotopes of an element present in a sample of that element
Isotopic abundance
28
Product released by test nuclear explosions in the 1950's and 1960s was the isotope ______
Stontium-90
29
Half-life of strontium-90
28.1years
30
It is a soft metal made of layers of large copper crystals. It can easily be drawn into wires because the layers of crystals can slip past one another.
Copper
31
Hammered copper sheets are (harder, softer) than drawn copper
Harder
32
The resulting alloy by mixing tin and copper is
Bronze
33
Process of recovering metal from ore by heating the ore
Smelting
34
Steel has ____% iron and ______%carbon
90-95% iron and 5-10% carbon
35
____________, with a half-life 5730 years can be used to date archeological objects as old as 60,000years
Carbon-14
36
Carbon-14 prent decays by beta emission to
Nitrogen-14
37
One ofthe oldest rocks found on the earth is_________ in Greenland
Granite outcrop(3.7 x 10⁹ yrs old)
38
Rock samples can be dated on the basis of their_____ and ____ content
Pb-206 and U-238
39
Age of solar system
4.6x10⁹ yrs
40
Naturaldecay product of U-238
Radon-222
41
Radon-222has a halflife of
3.8days
42
Radon-222 decays naturally and produces two harmful alpha emitters
Polonium-218 and Polonium-214
43
High-energy radiation damages tissue by
Causing ionization( the radiation knocke electrons out of the molecules that make up the tissue, therby forming unstable ions)
44
Compounds that have unpaired electrons are called
Free radicals or radicals
45
The inorganic material which makes up about 70% of bone by dry weight
Hydroxyapatite(Ca5(PO4)3OH)
46
Organic components of bone are
Collagen fibers
47
Use as Astringent(external)
Silver nitrate(AgNO3) and zinc oxide(ZnO)
48
Used as Radiopaque medium for Xray works
Barium Sulfate(BaSO4)
49
Used as plaster cast
Calcium Sulfate(CaSO4)
50
Used to treat iron deficiency
Iron Sulfate(FeSO4)
51
Used as Anti-infective (external)
Potassium permanganate(KMnO4)
52
Used as Diuretic
Potassium nitrate(KNO3)
53
Used to treat manic depression
Litium carbonate(Li2CO3)
54
Used as cathartic
Magnesium sulfate(MgSO4)
55
Used as antacid
Sodium bicarbonate(NaHCO3)(baking soda)
56
Used as iodine for thyroid hormones
Sodium iodide(NaI)
57
Used to acidify the digestive system
Ammonium chloride(NH4Cl)
58
Used as expectorant
Ammonium carbonate(NH4)2CO3)
59
Used to strenthen teeth
Tin(II) fluoride (SnF2)
60
A colorless gas , with a 11 valence electrons. It forms as a by product during combustion of fossil fuels
Nitric oxide
61
An apparatus that generates an electric current by using a redox reaction
Voltaic cell or battery
62
Which states of matter have a definite volume?
solids and liquids
63
Does the chemical nature of a substance change
when it melts from a solid to a liquid?
No, melting is a physical change
64
If the recommended dose
of a drug is 445 mg for a 180 lb man, what would be
a suitable dose for a 135 lb man?
334
65
How does the body react
to hypothermia?
The body shivers. Further temperature lowering
results in unconsciousness and then death.
66
Which would make a
more efficient cold compress, ethanol or methanol?
Methanol, because its higher specific heat allows it to
retain the heat longer.
67
Shivering is the body’s response to increase the body
temperature. What kind of energy is generated by
shivering?
kinetic energy
68
You have samples of urea (a solid at room tempera-
ture) and pure ethyl alcohol (a liquid at room tem-
perature). Which technique or techniques would you
use to measure the amount of each substance?
Weigh the solid urea on a balance, and measure the
liquid with a graduated cylinder.
69
Many substances that are involved in chemical reac-
tions in the human body (and in all organisms) con-
tain carbon, hydrogen, oxygen, and nitrogen arranged
in specific patterns. Would you expect new medica-
tions to have features in common with these sub-
stances, or would you expect them to be drastically
different? What are the reasons for your answer?
New medications would consist of the same elements,
and many of the fundamental patterns would be similar
70
You have a water sample that contains a contami-
nant you want to remove. You know that the contam-
inant is much more soluble in diethyl ether than it
is in water. You have a separatory funnel available.
Propose a way to remove the contaminant.
Diethyl ether is less dense than water and insoluble
in it. Put the water sample and the diethyl ether in the separatory funnel. The contaminant will dissolve in the diethyl
ether, leaving the water sample purified.
71
The atomic weight of lithium is 6.941 amu. Lithium has only two naturally occurring iso-
topes: lithium-6 and lithium-7. Estimate which isotope is in greater natural abundance.
Lithium-7 is the more abundant isotope
72
The atomic weight of lithium is 6.941 amu. Lithium has only two naturally occurring iso-
topes: lithium-6 and lithium-7. Estimate which isotope is in greater natural abundance.
Lithium-7 is the more abundant isotope
73
When 2.16 g of mercury oxide is heated, it decom-
poses to yield 2.00 g of mercury and 0.16 g of oxygen.
Which law is supported by this experiment?
the law of conservation of mass
74
It has been said that “the number of protons deter-
mines the identity of the element.” Do you agree or
disagree with this statement? Explain.
The statement is true in the sense that the number of
protons (the atomic number) determines the identity of the
atom.
75
If each of the atoms acquired two
more neutrons, what element would each then be?
Each would still be the same element because the
number of protons has not changed.
76
an atom with an unequal number of
protons and electrons.
Ion
77
atoms with the same number of protons,
but a different number of neutrons in their nuclei.
Isotopes
78
The isotope carbon-11 does not occur in nature but
has been made in the laboratory. This isotope is used
in a medical imaging technique called positron emis-
sion tomography (PET, see Section 3.7A). Give the
number of protons, neutrons, and electrons in an
atom of carbon-11
Carbon-11 has 6 protons, 6 electrons, and 5 neutrons.
79
How many metals, metalloids, and nonmetals are
there in the third period of the Periodic Table?
In Period 3, there are three metals (Na, Mg, Al), one
metalloid (Si), and four nonmetals (P, S, Cl, Ar).
80
Which period(s) in the Periodic Table contain more
nonmetals than metals? Which contain more metals
than nonmetals?
Periods 1, 2, and 3 contain more nonmetals than
metals. Periods 4, 5, 6, and 7 contain more metals than
nonmetals.
81
Why do the elements in column 1A of the Periodic
Table (the alkali metals) have similar but not identi-
cal properties?
The properties are similar because all of them have
similar outer-shell electron configurations. They are not
identical because each has a different number of filled
inner shells.
82
You are presented with a Lewis dot structure of ele-
ment X as X . To which two groups in the Periodic
Table might this element belong?
The element might be in Group 2A, whose members
have two valence electrons. It might also be helium in
Group 8A.
83
Which are the two most
abundant elements, by weight, in
(a) The Earth’s crust?
oxygen and silicon
84
Which are the two most
abundant elements, by weight, in
(b) The human body?
oxygen and carbon.
85
Why is strontium-90
more dangerous to humans than most other radio-
active isotopes that were present in the Chernobyl
fallout?
Calcium is an essential element in human bones and
teeth. Because strontium behaves chemically much like calcium, strontium-90 gets into our bones and teeth and gives
off radioactivity for many years directly into our bodies.
86
Copper is a soft metal.
How can one make it harder?
by hammering
87
o isotopes of the heavy elements (for example,
those from atomic number 37 to 53) contain more,
the same, or fewer neutrons than protons?
For elements with atomic numbers less than that of
iron (Fe), the number of neutrons is close to the number of
protons. Elements with atomic numbers greater than that
of Fe have more neutrons than protons. Therefore, heavy
elements have more neutrons than protons
88
Suppose that you face a problem similar to
Mendeleev: You must predict the properties of an
element not yet discovered. What will element 118
be like if and when enough of it is made for chemists
to study its physical and chemical properties?
Element 118 will be in Group 8A. Expect it to be a gas
that forms either no compounds or very few compounds.
89
What kind of emission does not result in
transmutation?
Gamma emission does not result in transmutation.
90
Polonium-218, a decay product of radon-222 (see
Chemical Connections 3B), has a half-life of 3 min.
What percentage of the polonium-218 formed will
remain in the lung 9 min after inhalation?
12.5%
91
The element radium is extremely radioactive. If you
converted a piece of radium metal to radium chloride
(with the weight of the radium remaining the same),
would it become less radioactive?
No, the conversion of Ra to Ra21 involves loss of
valence electrons, which is not a nuclear process and, therefore, does not involve a change in radioactivity.
92
Suppose 50.0 mg of potassium-45, a beta emitter,
was isolated in pure form. After one hour, only
3.1 mg of the radioactive material was left. What
is the half-life of potassium-45?
15 min
93
If you work in a lab containing radioisotopes emit-
ting all kinds of radiation, from which emission
should you seek most protection?
Gamma radiation has the greatest penetrating power;
therefore, it requires the largest amount of shielding.
94
You work in a lab and it is known that radioactivity
is being emitted with an intensity of 175 mCi at
a distance of 1.0 m from the source. How far, in
meters, from the source should you stand if you
wish to be subjected to no more than 0.20 mCi?
30 m
95
What property is measured each term?
(a) Rad (b) Rem (c) Roentgen
(d) Curie (e) Gray (f ) Becquerel
(g) Sievert
(a) amount of radiation absorbed from the radiation
source (b) effective dose absorbed by humans or tissue
(c) effective energy delivered (d) intensity of radiation
(e) amount of radiation absorbed by tissues from the radiation source (f) intensity of radiation (g) effective dose
absorbed by humans or tissues
96
Why does exposure of a hand to alpha rays not cause
serious damage to the person, whereas entry of an
alpha emitter into the lung as an aerosol produces
very serious damage to the person’s health?
Alpha particles have so little penetrating power that
they are stopped by the thin skin on the hand. If they get
into the lungs, however, the thin membranes offer little
resistance to them, and they then damage the cells of
the lungs.
97
Assuming the same amount of effective radiation, in
rads, from three sources, which would be the most
damaging to the tissues: alpha particles, beta parti-
cles, or gamma rays?
Alpha particles are the most damaging to tissue
98
Assuming the same amount of effective radiation, in
rads, from three sources, which would be the most
damaging to the tissues: alpha particles, beta parti-
cles, or gamma rays?
Iodine-131, which is concentrated in the thyroid,
where the radiation can induce thyroid cancer.
99
In 1986, the nuclear reactor in Chernobyl had an
accident and spewed radioactive nuclei that were
carried by the winds for hundreds of miles. Today,
among the child survivors of the event, the most
common damage is thyroid cancer. Which radioactive
nucleus do you expect to be responsible for these
cancers?
Iodine-131, which is concentrated in the thyroid,
where the radiation can induce thyroid cancer.
100
radioactive isotope with its proper use
(a) Cobalt-60 is used for cancer therapy.
(b) Thallium-201 is used in heart scans and exercise
stress tests.
(c) Tritium is used to measure the water content of
the body
(d) Mercury-197 is used for kidney scans.
101
Assuming that one proton and two neutrons will
be produced in an alpha-bombardment fusion reac-
tion, which target nucleus would you use to obtain
berkelium-249?
curium-248 as the target nucleus.
102
A new element was formed when lead-208 was
bombarded by krypton-86. One could detect four
neutrons as the product of the fusion. Identify the
new element.
The new element is the sought-after element 118
103
Why is it accurate to
assume that the carbon-14 to carbon-12 ratio in a
living plant remains constant over the lifetime of
the plant?
The assumption of a constant carbon-14 to carbon-12
ratio rests on two assumptions: (1) that carbon-14 is continually generated in the upper atmosphere by the production
and decay of nitrogen-14,and (2) that carbon-14 is incorporated into carbon dioxide,
CO2, and other carbon compounds are then distributed
worldwide as part of the carbon cycle. The continual formation of carbon-14; transfer of the isotope within the oceans,
atmosphere, and biosphere; and the decay of living matter
keep the supply of carbon-14 constant.
104
Carbon-14 dating of the
Shroud of Turin indicated that the plant from which
the shroud was made was alive around AD 1350. To
how many half-lives does this correspond
a bit more than 0.1 (or 10%) of the half-life of carbon-14
105
How does radon-222 pro-
duce polonium-218?
alpha emission
106
Neon-19 and sodium-20 are positron emitters. What
products result in each case
Neon-19 decays to fluorine-19 and sodium-20 decays
to neon-20
107
Do the curie and the becquerel measure the same or
different properties of radiation?
Yes. Both the curie and the becquerel have units
of disintegrations/second, a measurement of radiation
intensity.
108
Which radiation will cause more ionization, Xrays
or radar?
X rays will cause more ionization than radar waves
because X rays have higher energy than radar waves.
109
Americium-241, which is used in some smoke detec-
tors, has a half-life of 432 years and is an alpha emit-
ter. What is the decay product of americium-241,
and approximately what percentage of the original
americium-241 will be still around after 1000 years?
The decay product is neptunium-237,less than 25% of the
original americium will remain after 1000 years(20.1%)
110
A patient is reported to have been irradiated by
a dose of 1 sievert in a nuclear accident. Is he in
mortal danger
One sievert is 100 rem. This dose is sufficient to cause
radiation sickness but not certain death.
111
e half-lives of some oxygen isotopes are as follows:
Oxygen-14: 71 s Oxygen-15: 124 s
Oxygen-19: 29 s Oxygen-20: 14 s
Oxygen-16 is the stable, nonradioactive isotope. Do
the half-lives indicate anything about the stability of
the other oxygen isotopes?
Oxygen-16 is stable because it has an equal number of
protons and neutrons. The other isotopes are unstable
because the numbers of protons and neutrons are unequal.
In this case, the greater the neutron/proton ratio, the
shorter the half-life of the isotope.
112
When Pb is bombarded with Ni, a new element
and six neutrons are produced. Identify the new
element.
new element is darmstadtium-266.
113
Why does electronegativity generally increase in
going up a column of the Periodic Table?
Electronegativity increases going up a column (group)
of the Periodic Table because valence electrons are in shells
closer to the electropositive nucleus. The decreasing distance of the valence electrons from the positively charged
nucleus causes the valence electrons to experience an
increasing force of attraction
114
Describe the structure of sodium chloride in the solid
state.
Sodium chloride in the solid state has each Na1 ion
surrounded by six Cl2 ions and each Cl2 ion surrounded by
six Na1 ions.
115
Why can’t hydrogen have more than two electrons in
its valence shell?
Hydrogen has the electron configuration 1s1. Hydrogen’s valence shell has only the 1s orbital, which can hold
a maximum of two electrons
116
Why is Li2 not a stable ion?
Li2 is not a stable ion because it has an unfilled
second shell.
117
Why does nitrogen have three bonds and one
unshared pair of electrons in covalent compounds?
Nitrogen has five valence electrons. By sharing three
more electrons with another atom or atoms, nitrogen can
achieve an outer-shell electron configuration that is the
same as that of neon, the noble gas nearest it in atomic
number. The three shared pairs of electrons may be in the
form of three single bonds, one double bond and one single
bond, or one triple bond. With each of these bonding combinations, there is one unshared pair of electrons on nitrogen
118
Why does oxygen have two bonds and two unshared
pairs of electrons in covalent compounds?
Oxygen has six valence electrons. By sharing two electrons with another atom or atoms, oxygen can achieve an
outer-shell electron configuration that is the same as that
of neon, the noble gas nearest it in atomic number. The two
shared pairs of electrons may be in the form of one double
bond or two single bonds. With either of these bonding
combinations, there are two unshared pairs of electrons
on oxygen
119
The ion O⁶ has a complete outer shell. Why is this
ion not stable?
O⁶ has a charge too concentrated for such a small
ion. It would take a tremendous amount of energy to form
such a small, highly charged species as O⁶
120
Both CO2 and SO2 have polar bonds. Account for the
fact that CO2 is nonpolar and SO2 is polar.
The difference in polarity arises because of their differences in shapes. CO2 is a linear molecule, and SO2 is a
bent molecule.
121
Is it possible for a molecule to have polar bonds and
yet have no dipole?
Yes, it is possible for a molecule to have polar bonds
and yet no permanent dipole. This result occurs when the
individual polar bonds act in equal but opposite directions,
as in CO2.
122
What are the three main
inorganic components of one dry mixture currently
used to create synthetic bone?
calcium dihydrogen phosphate, calcium phosphate,
and calcium carbonate
123
What is a medical use
of barium sulfate?
barium sulfate is used to visualize the gastrointestinal tract by x-ray examination.
124
What is the main metal
ion present in bone and tooth enamel?
Ca21 is the main metal ion present in bone and tooth
enamel
125
Explain why argon does not form either (a) ionic
bonds or (b) covalent bonds.
Argon already has an octet with eight valence electrons in its outer shell; therefore, (a) it does not donate or
accept electrons to form ions, and (b) it does not need to
form covalent bonds by sharing electrons.
126
If you read the labels of sun-blocking lotions, you will
find that a common UV-blocking agent is a compound
containing zinc. Name and write the formula of this
zinc-containing compound.
The compound is zinc oxide, ZnO
127
We are constantly warned about the dangers of “lead-
based” paints. Name and write the formula for a lead-
containing compound found in lead-based paints
Lead(IV) oxide, PbO2, and lead(IV) carbonate,
Pb(CO3)2, are used as white pigments in paints.
128
Iron forms Fe2+ and Fe3+ ions. Which ion is found in
the over-the-counter preparations intended to treat
“iron-poor blood”?
Fe2+
129
Perchloroethylene, which is a liquid at room temper-
ature, is one of the most widely used solvents for
commercial dry cleaning. It is sold for this purpose
under several trade names, including Perclene. Does
this molecule have polar bonds? Is it a polar mole-
cule? Does it have a dipole?
Perchloroethylene has four polar covalent C Cl
bonds, but it is not a polar compound. The molecule lacks a
dipole because the polar covalent C Cl bonds act in equal,
but opposite directions.
130
A single atom of cerium weighs just about twice as
much as a single atom of gallium. What is the weight
ratio of 25 atoms of cerium to 25 atoms of gallium?
2:1
131
Calcium oxide is prepared by heating limestone
(calcium carbonate, CaCO3) to a high temperature,
at which point it decomposes to calcium oxide and
carbon dioxide. Write a balanced equation for this
preparation of calcium oxide.
CaCO3(s) ----->CaO(s)+ CO2(g)
132
The rusting of iron is a chemical reaction of iron with
oxygen in the air to form iron(III) oxide. Write a bal-
anced equation for this reaction.
4Fe(s) + 3O2(g) ----->2Fe2O3(s)
133
Can reduction take place without oxidation?
No. In oxidation there is a loss of electrons, and there
must be some species to accept those electrons—that is,
some species that is reduced.
134
What is the difference between exothermic and
endothermic?
An exothermic chemical reaction or process releases
heat as a product.
An endothermic chemical reaction or process absorbs heat
as a reactant.
135
The oxidation of glucose, C6H12O6, to carbon dioxide
and water is exothermic. The heat liberated is the
same whether glucose is metabolized in the body or
burned in air.
Calculate the heat liberated when 15.0 g of glucose is
metabolized to carbon dioxide and water in the body.
55.8 kcal.
136
A plant requires approximately 4178 kcal for the
production of 1.00 kg of starch (Section 19.6A) from
carbon dioxide and water.
(a) Is the production of starch in a plant an exother-
mic process or an endothermic process?
(b) Calculate the energy in kilocalories required by
a plant for the production of 6.32 g of starch.
(a) The synthesis of starch is endothermic.
(b) 26.4 kcal
137
How does fluoride ion
protect the enamel against tooth decay?
Fluoride reacts with Ca10(PO4)6(OH)2 in the enamel by
exchanging the F2 ions for OH2 ions, forming Ca10(PO4)6F2,
which is less soluble under the acidic conditions found in
the mouth.
138
Chlorophyll, the compound responsible for the green
color of leaves and grasses, contains one atom of
magnesium in each molecule. If the percentage by
weight of magnesium in chlorophyll is 2.72%, what
is the molecular weight of chlorophyll?
894 amu
139
states that for a gas at constant temper-
ature, the volume of the gas is inversely proportional
to the pressure
Boyle’s law
140
states that the volume of a gas at con-
stant pressure is directly proportional to the tempera-
ture in kelvins.
Charles’s law
141
states that for gas at constant
volume, the pressure is directly proportional to the
temperature in kelvins.
Gay-Lussac’s law
142
states that equal volumes of gases
at the same temperature and pressure contain the
same number of molecules.
Avogadro’s law
143
states that the
total pressure of a mixture of gases is the sum of the
partial pressures of each individual gas.
Dalton’s law of partial pressures
144
explains the behav-
ior of gases. Molecules in the gaseous state move
rapidly and randomly, allowing a gas to fill all the
available space of its container.
kinetic molecular theory
145
are responsi-
ble for the condensation of gases into the liquid state
and for the solidification of liquids to the solid state.
Intermolecular forces of attraction
146
the energy of intermolecular
attractive forces at the surface of a liquid.
Surface tension
147
the pressure of a vapor (gas)
above its liquid in a closed container. The vapor
pressure of a liquid increases with increasing
temperature.
Vapor pressure
148
the temperature
at which its vapor pressure equals the atmospheric
pressure. determined
by (1) the nature and strength of the intermolecular
forces between its molecules, (2) the number of sites
for intermolecular interaction, and (3) molecular
shape
boiling point
149
the temperature at which a
substance changes from the solid state to the liquid
state
melting point
150
the formation of a solid from
a liquid.
Crystallization
151
involves a change of
matter from one physical state to another—that is,
from a solid, liquid, or gaseous state to any one of the
other two state
phase change
152
any part of a system that looks uniform
throughout.
phase
153
change from a solid state directly
to a gaseous state.
Sublimation
154
the heat necessary to convert 1.0 g
of any solid to a liquid.
Heat of fusion
155
the heat necessary to con-
vert 1.0 g of any liquid to the gaseous state.
Heat of vaporization
156
Does the density of a gas increase, decrease, or stay
the same as the pressure increases at constant tem-
perature? As the temperature increases at constant
pressure?
Density increases as pressure increases and decreases
as temperature increases.
157
Which forces are stronger, intramolecular covalent
bonds or intermolecular hydrogen bonds?
Intramolecular covalent bonds are stronger than
intermolecular hydrogen bonds
158
Can water and dimethyl sulfoxide, (CH3)2S=O,
form hydrogen bonds between them?
yes
159
Ethanol, C2H5OH, and carbon dioxide, CO2, have
approximately the same molecular weight, yet car-
bon dioxide is a gas at STP and ethanol is a liquid.
How do you account for this difference in physical
property?
Ethanol is a polar molecule and engages in intermolecular hydrogen bonding through its OH group. Carbon
dioxide is a nonpolar molecule, and the only forces of
attraction between its molecules are weak London dispersion forces. The stronger hydrogen bonds require more
energy (higher temperature) to break before vaporizing.
160
Which compound has a higher boiling point:
butane, C4H10, or hexane, C6H14?
Hexane has the higher boiling point.
161
Which types of solids have the highest melting
points? Which have the lowest melting points?
Ionic and network solids have the highest melting
points. Molecular solids have the lowest melting points.
162
The normal boiling point of a substance depends
on both the mass of the molecule and the attractive
forces between molecules. Arrange the compounds
in each set in order of increasing boiling point and
explain your answer:
(a) HCl, HBr, HI (b) O2, HCl, H2O2
(a) HCl
163
When iodine vapor hits a cold surface, iodine crystals
form. Name the phase change that is the reverse of
this condensation.
sublimation
164
Which has lower entropy,
a gas at 100°C or one at 200°C?
When the temperature of a substance increases, so
does its entropy. Therefore, a gas at 100°C has a lower
entropy than the same gas at 200°C.
165
What happens when
a person lowers the diaphragm in his or her chest
cavity?
When the diaphragm is lowered, the volume of the
chest cavity increases, lowering the pressure in the lungs
relative to the atmospheric pressure. Air at atmospheric
pressure then rushes into the lungs, beginning the breathing process.
166
In a sphygmomanometer
one listens to the first tapping sound as the constric-
tive pressure of the arm cuff is slowly released. What
is the significance of this tapping sound?
The first tapping sound one hears is the systolic pressure, which occurs when the sphygmomanometer pressure
matches the blood pressure when the ventricle contracts,
pushing blood into the arm.
167
If you fill a glass bottle
with water, cap it, and cool to -10°C, the bottle will
crack. Explain.
When water freezes, it expands (water is one of the few
substances that expands on freezing) and will crack the bottle when the ice expansion exceeds the volume of the bottle.
168
Why is it difficult to compress a liquid or a solid?
It is difficult to compress liquids and solids because
their molecules are already very close together and there is
very little empty space between them.
169
Why do aerosol cans carry the warning “Do not
incinerate”?
Aerosol cans already contain gases under high pressure. Gay-Lussac’s law predicts that the pressure inside the
can will increase with increasing temperature, with the
potential of explosive rupture of the can, causing injury
170
Why does the temperature of a liquid drop as a
result of evaporation?
The temperature of a liquid decreases during evaporation because the molecules with higher kinetic energy leave
the liquid, which decreases the average kinetic energy of
those molecules remaining in the liquid. The temperature
of the liquid is directly proportional to the average kinetic
energy of the molecules in the liquid state. Therefore the
temperature decreases as the average kinetic energy
decreases.
171
Red blood cells in hypotonic solution swell and
burst, a process called
hemolysis.
172
Red blood cells in hypertonic solution shrink,
a process called
crenation.
173
used to separate
large molecules from smaller ones.
dialysis,
174
Colloids exhibit a chaotic random motion, called
Brownian motion.
175
familiar example of solutions of each of these
types:
(a) Liquid in liquid
(b) Solid in liquid
(c) Gas in liquid
(d) Gas in gas
(a) wine (ethanol in water)
(b) saline solution (NaCl dissolved in water)
(c) carbonated water (CO2 dissolved in water)
(d) air (O2 and N2)
176
We dissolved 0.32 g of aspartic acid in 115.0 mL of
water and obtained a clear solution. After two days
standing at room temperature, we notice a white
powder at the bottom of the beaker. What may have
happened?
One possible explanation is that the prepared aspartic
acid solution was unsaturated. Over two days, some of the
solvent (water) may have evaporated and the solution
became supersaturated, precipitating the excess aspartic
acid as a white solid
177
Suppose that we have a stain on an oil painting that
we want to remove without damaging the painting.
The stain is not water-insoluble. Knowing the polari-
ties of the following solvents, which one would we try
first and why?
(a) Benzene, C6H6
(b) Isopropyl (rubbing) alcohol, C3H7OH
(c) Hexane, C6H14
Isopropyl alcohol would be a good first choice. The oil
base in the paint is nonpolar. Both benzene and hexane are
nonpolar solvents and may dissolve the paint, destroying
the painting.
178
The solubility of aspartic acid in water is 0.500 g in
100 mL at 25°C. If we dissolve 0.251 g of aspartic
acid in 50.0 mL of water at 50°C and let the solution
cool to 25°C without stirring, shaking, or otherwise
disturbing the solution, would the resulting solution
be a saturated, unsaturated, or supersaturated solu-
tion?
The solubility of aspartic acid at 25°C in 50.0 mL of
water is 0.250 g of solute. Assuming that no precipitation occurs, the cooled solution will contain 0.251 g of aspartic
acid in 50.0 mL of water and will be supersaturated by
0.001 g of aspartic acid.
179
If a bottle of beer is allowed to stand for several
hours after being opened, it becomes “flat” (it loses
CO2). Explain.
According to Henry’s law, the solubility of a gas in
a liquid is directly proportional to the pressure. A closed
bottle of a carbonated beverage is under excess CO2 pressure. After the bottle is opened, the excess CO2 pressure
is released and the CO2 escapes from solution as bubbles
of gas.
180
A student has a stock solution of 30.0% w/v H2O2
(hydrogen peroxide). Describe how the student
should prepare 250 mL of a 0.25% w/v H2O2 solution
Place 2.1 mL of 30.0% w/v H2O2 into a 250-mL volumetric flask, add some water, swirl to mix completely, and
fill the flask with water to the 250 mL mark.
181
A student has a bottle labeled 0.750% albumin solu-
tion. The bottle contains exactly 5.00 mL. How much
water must the student add to make the concentra-
tion of albumin become 0.125%?
The total volume of the diluted solution will be 30.0 mL.
Start with 5.0 mL of solution and add 25.0 mL of water to
reach a final volume of 30.0 mL.
182
Dioxin is considered to be poisonous in concentra-
tions above 2 ppb. If a lake containing 1 107 L has
been contaminated by 0.1 g of dioxin, did the concen-
tration reach a dangerous level?
Dioxin concentration 0.01 ppb dioxin.
No, the dioxin level in the lake did not reach a dangerous
level.
183
classify the follow-
ing systems as homogeneous, heterogeneous, or col-
loidal mixtures.
(a) Physiological saline solution
(b) Orange juice
(c) A cloud
(d) Wet sand
(e) Suds
(f ) Milk
(a) homogeneous (b) heterogeneous (c) colloidal
(d) heterogeneous (e) colloidal (f) colloidal
184
A solution of protein is transparent at room tempera-
ture. When it is cooled to10°C, it becomes turbid.
What causes this change in appearance?
As the temperature of the solution decreases, the
protein molecules aggregate and form a colloidal mixture.
The turbid appearance is the result of the Tyndall effect.
185
A 0.9% NaCl solution is isotonic with blood plasma.
Which solution would crenate red blood cells?
(a) 0.3% NaCl
(b) 0.9 M glucose (MW 180)
(c) 0.9% glucose
Red blood cells will undergo crenation (shrink) in
a hypertonic solution. A 0.9% NaCl solution is 0.3 osmol.
Solution (b) is 0.9 osmol (hypertonic) and will crenate
red blood cells.
186
What makes normal
rainwater slightly acidic?
Carbon dioxide (CO2) dissolves in rainwater to form
a dilute solution of carbonic acid (H2CO3), which is a
weak acid.
187
What is nitrogen
narcosis?
Nitrogen dissolved in the blood can lead to a narcotic
effect referred to as “rapture of the deep,” which is similar
to alcohol-induced intoxication
188
What is the chemical
formula for the main component of limestone and
marble?
The main component of limestone and marble is
calcium carbonate, CaCO3.
189
What is the minimum
pressure on sea water that will force water to flow
from the concentrated solution into the dilute
solution?
The minimum pressure required for reverse osmosis
in the desalinization of sea water exceeds 100 atm (the
osmotic pressure of sea water).
190
A manufacturing error
occurred in the isotonic solution used in hemodialy-
sis. Instead of 0.2% NaHCO3, 0.2% of KHCO3 was
added. Did this error change the labeled tonicity of
the solution? If so, is the resulting solution hypotonic
or hypertonic? Would such an error create an elec-
trolyte imbalance in the patient’s blood? Explain.
Yes, the change in composition made a change in the
tonicity. The error in replacing NaHCO3 with KHCO3
resulted in a hypotonic solution and an electrolyte imbalance by reducing the number of ions (osmolarity) in solution.
191
When a cucumber is put into a saline solution to
pickle it, the cucumber shrinks; when a prune is put
into the same solution, the prune swells. Explain
what happens in each case.
When a cucumber is placed in a saline solution, the
osmolarity of the saline solution is greater than that of the
water in the cucumber, so water moves from the cucumber
to the saline solution and the cucumber shrinks. When a
prune (a partially dehydrated plum) is placed in the same
solution, it expands because the osmolarity inside the
prune is greater than that of the saline solution, so water
moves from the saline solution to inside the prune, causing
the prune to expand.
192
Two bottles of water are carbonated, with CO2 gas
being added, under 2 atm pressure and then capped.
One bottle is stored at room temperature; the other
is stored in the refrigerator. When the bottle stored
at room temperature is opened, large bubbles escape,
along with a third of the water. The bottle stored in
the refrigerator is opened without frothing or bub-
bles escaping. Explain.
The solubility of a gas in a solvent is directly proportional to the pressure (Henry’s law) of the gas and is
inversely proportional to the temperature. The dissolved
carbon dioxide formed a saturated solution in water when
bottled under 2 atm pressure. When the bottles are opened
at atmospheric pressure, the gas becomes less soluble. The
carbon dioxide becomes supersaturated in water at room
temperature and 1 atm, and thus escapes as bubbles and
frothing. In the other bottle, the solution of carbon dioxide
in water is unsaturated at a lower temperature and does
not lose carbon dioxide as readily
193
We know that a 0.89% saline (NaCl) solution is iso-
tonic with blood. In a real-life emergency, we run out
of physiological saline solution and have only KCl as
a salt and distilled water. Would it be acceptable to
make a 0.89% aqueous KCl solution and use it for
intravenous infusion? Explain.
No, it would not be acceptable to use an 0.89% KCl
solution for intravenous infusions because it will not be isotonic with blood. KCl has a higher molecular weight than
NaCl; consequently, its osmolarity will be smaller.
194
Synovial fluid that exists in joints is a colloidal solu-
tion of hyaluronic acid (Section 20.6A) in water.
When a biochemist wants to isolate hyaluronic acid
from synovial fluid, he or she adds ethanol, C2H6O,
to bring the solution to 65% ethanol. The hyaluronic
acid precipitates upon standing. What makes the
hyaluronic acid solution unstable and causes it to
precipitate?
The ethanol molecules displace water molecules from
the solvation layer of the hyaluronic acid, allowing the
hyaluronic acid molecules to stick together upon collision
and form aggregates that precipitate.
