CHAPTER 2,3-5
A mole of methanol (CH3OH) weighs 32 g. The number of grams of methanol that are needed to produce 1 L of a 1 millimolar solution is __________.
0.032 g
Urine, at pH 6, contains __________ H+ as household bleach, at pH 13.
10,000,000 times as much
A solution at pH 10 contains __________ than the same amount of solution at pH 8.
100 times less H+
A straight-chain carbon compound constructed from __________ must contain at least one carbon-carbon double bond.
6 hydrogen atoms and 3 carbon atoms
When one or more pairs of valence electrons are shared by two neutral atoms, what type of bond is formed?
A covalent bond
What is ATP's importance in the cell?
ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes.
The absorption of human-generated CO2 by the oceans __________.
All of the listed responses are correct.
Which of the following functional groups increases the solubility of organic compounds in water?
All of the listed responses are correct.
Which of the following groups is capable of hydrogen bonding with an oxygen atom on another functional group?
All of the listed responses are correct.
Which of the following four statements, if any, is true regarding essential elements and living organisms?
Although all forms of life require iron, other elements are required only by certain species.
Which of the following is an organic molecule?
CH4
What is the reason carbon atoms are the most versatile building blocks of the molecules used by living organisms?
Each carbon atom acts as an intersection point from which a molecule can branch off in up to four directions.
Which of the following has negligible mass?
Electron
What are the four most abundant elements found in living systems?
Hydrogen, oxygen, nitrogen, and carbon
Generally, animals cannot digest (hydrolyze) the glycosidic linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass?
Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units.
Which of the following subatomic particles has appreciable mass and lacks a charge?
Neutron
Which of these is a thiol?
None of the listed responses is correct.
Pharmaceutical companies are selling billions of dollars' worth of single-enantiomer drugs. Why might it be important to use only one form of an enantiomer?
One enantiomer may provide an effective treatment whereas the other may be ineffective or even toxic.
Which of the following molecules has a carboxyl functional group?
R—COOH
Which of the following molecules is a weak acid?
R—COOH
Which of the following molecules is a weak base?
R—NH2
You can fill a glass of water to just slightly above the rim without it spilling over the glass. What property of water best explains this phenomenon?
Surface tension
__________ is an emergent property of water that allows insects like the raft spider to walk on water.
Surface tension
Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?
The absorption of heat by the breaking of hydrogen bonds.
Which statement is true of all atoms that are anions?
The atom has more electrons than protons.
Which of the following examples best describes a unique functional property of the carboxyl group?
The covalent bond between oxygen and hydrogen is so polar that hydrogen ions tend to dissociate from oxygen reversibly.
A pharmaceutical company was forced to recall a pain reliever medication that had been linked to the fatalities of several hundred people. Analysis of the recalled drug revealed the presence of two isomers due to an asymmetrical carbon atom in the drug molecule. What can be hypothesized from this observation?
The isomers are enantiomers, with one having toxic effects on humans.
Which of the following statements is true about chemical reactions?
They involve the making and breaking of chemical bonds.
A substance that reduces the hydrogen ion concentration of a solution is __________.
a base
The carbon atom is tetravalent, which means that __________
a carbon atom can complete its valence shell by forming four covalent bonds
An acid is __________.
a compound that donates hydrogen ions to a solution
Water molecules have __________ than molecules of similar size, such as ammonia and methane, reflecting its capacity to absorb large amounts of heat.
a higher boiling point
In a hydrolysis reaction, __________, and in this process water is __________.
a polymer is broken up into its constituent monomers ... consumed
What is the three-dimensional shape created by hybrid orbitals that are formed when a carbon atom is covalently bonded with four other atoms?
a tetrahedron with carbon in the center
Orbitals are best described as __________.
a three-dimensional space where an electron spends most of its time with no more than 1 other electron, forming a pair
Stanley Miller's experiments were significant because he demonstrated that __________.
a variety of simple organic compounds could be spontaneously synthesized from components in Earth's primitive atmosphere
Choose the pair of terms that correctly completes this sentence about functional groups in organic chemistry: Carboxyl is to __________ as __________ is to base.
acid ... amino
A compound that donates hydrogen ions to a solution is __________.
an acid
Hydrophilic molecules __________.
are charged molecules that are attracted to the partial charge of the water molecule
Radioactive tracers _________.
are important tools in biological research and medicine
Trace elements __________.
are required by an organism in minute quantities
Hydrophobic molecules __________.
are uncharged, nonionic substances that seem to repel water
Isotopes of an element will always differ in __________.
atomic mass
Ionic bonds form as a result of __________.
attraction between ions that have opposite charges
The ability of water molecules to form hydrogen bonds with other water molecules and water's ability to dissolve substances that have charges or partial charges are __________.
both caused by water's partial charges
Which of these is found in all amino acids?
both —COOH and —NH2
Molecular mimics __________.
can produce similar effects as the naturally occurring molecules
Which element is always associated with organic chemistry?
carbon
What are the six most important chemical elements of life?
carbon, nitrogen, oxygen, hydrogen, phosphate, sulfur
Which functional group would you predict is part of abscisic acid?
carboxyl group
Which of the following is a polymer?
cellulose, a plant cell wall component
The phenomenon responsible for maintaining the upward movement of water through a vessel is __________.
cohesion
Water moves up a plant because of hydrogen bonds by a process called __________.
cohesion and adhesion
The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a(n) __________ bond.
covalent
What is the process by which monomers are linked together to form polymers?
dehydration reaction
Carbohydrates are used in our bodies mainly for __________.
energy storage and release
Nonpolar covalent bonds are always formed from atoms that are __________.
equal in their electronegativity
The number of protons in an uncharged atom __________.
equals the number of electrons
Weak chemical bonds such as hydrogen bonds __________.
form when a hydrogen atom that is covalently bonded to an electronegative atom like oxygen or nitrogen is attracted to another electronegative atom
Which of the following carbohydrate molecules has the lowest molecular mass?
glucose
A polysaccharide that is used for storing energy in human muscle and liver cells is __________.
glycogen
In a process called radiometric dating, scientists measure the __________ of an isotope to determine the age of the Earth.
half-life
Sweating has a cooling effect because of water's high __________.
heat of vaporization
The two compounds Question #15 image Question #15 image are related to each other by being __________.
hydrocarbons, isomers, organic compounds, and double-bonded compounds
When ice forms, the __________ are farther apart than in liquid water, allowing the ice to form an organized crystal structure and float.
hydrogen bonds
Nonpolar molecules that cluster away from water molecules are called __________ molecules.
hydrophobic
Which of the following are properties of hydrocarbons?
hydrophobic, nonpolar, good source of stored energy
Using modern equipment, a former graduate student of Stanley Miller recently reanalyzed the sample results of volcano simulation experiments that Miller conducted along with his classic experiment described in the text. This reanalysis did which of the following?
identified additional organic compounds that had not been found by Miller
When a very electronegative atom strips a valence electron away from its partner, __________ form.
ions
When the proton number and electron number are unequal, the atom or molecule __________.
is an ion
A covalent bond __________.
is the sharing of a pair of valence electrons by two atoms
The molecular shape of a biological molecule is important because __________.
it determines how biological molecules recognize and respond to one another
When the pH of a solution shifts from 3 to 7, the hydrogen ion concentration has changed, and __________.
it has decreased by 10,000 times
The fact that oxygen is an atom that is strongly electronegative means that __________.
it more strongly pulls shared electrons toward itself when forming a covalent bond with a less electronegative atom
Adding a base tends to __________ of a solution.
lower the hydrogen ion concentration and increase the pH
All of the following are hydrogen bonding properties except __________.
nonpolar covalent bonding
The chemical characteristics or reactivity of an element depend mostly on the __________.
number of electrons in its outermost shell
A covalent bond is likely to be polar if __________.
one of the atoms sharing electrons is much more electronegative
Hydrogen bonds occur when __________.
partial opposite charges on molecules come close enough to attract each other
Which of the following functional groups is associated with a release of energy when removed from the carbon skeleton with water?
phosphate group
Cellulose is a __________ made of many __________.
polymer ... glucose molecules
In chemical reactions, the __________ are the starting materials that are converted into the __________.
reactants; products
Ethanol, propanol, and methanol are three simple alcohols. They can be grouped together because they __________.
share the same functional group: a hydroxyl
In what polysaccharide form do plants store glucose to be available later as an energy source?
starch
The polysaccharide that you are most likely to have eaten recently is __________.
starch
Glucose has a molecular mass of 180 daltons. To make a 2-molar (2 M) solution of glucose, __________.
stir 360 g of glucose in water to dissolve the sugar, and then add enough water to bring the total volume of the solution up to 1 L
Buffers are __________.
substances that minimize changes in the concentration of H+ and OH- in a solution
The specific heat of a substance is __________.
the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1°C
Adhesion is best described as __________.
the clinging of one substance to another substance
The reactivity of an atom arises from __________.
the existence of unpaired electrons in the valence shell
The amount of heat required to convert 1 g of any substance from the liquid to the gaseous state is defined as __________.
the heat of vaporization of that substance
Water is a polar molecule. This means that __________.
the opposite ends of the molecule have opposite electrical charges
The amount of heat required to change the temperature of 1 g of any substance by one °C is defined as __________.
the specific heat of that substance
In ionic interactions, __________.
the transfer of valence electrons results in a completed valence shell for each ion
The partial charges on a water molecule occur because of __________.
the unequal sharing of electrons between the hydrogen and the oxygen atoms of a water molecule
The difference between a stable isotope and an unstable isotope of an element is that __________.
the unstable isotope has a nucleus that decays spontaneously, is radioactive, and can be transformed into an atom of another element
One characteristic shared by sucrose, lactose, and maltose is that __________.
they are all disaccharides
A molecule has one carbon-carbon double bond and four monovalent atoms or groups. How many different cis-trans isomers exist for this molecule?
two
The behavior of an atom depends on the __________.
valence electrons in the outermost electron shell
Which of the following functional groups is present in all amino acids?
—NH2
