R = reactants P = products
For the above energy profiles, which reaction has the lowest activation energy?
A) a
B) b
C) c
D) d
E) All have the same activation energy.
Answer:
What is the purpose of a salt-bridge?
A) to allow ions to migrate between solutions
B) to allow people to cross over salt water
C) to allow electrons to migrate through solutions
D) to allow salt to form in the oxidation-reduction reactions
E) none of the above
Answer:
Which has the greatest number of atoms?
A) 28 g of nitrogen,
B) 32 g of oxygen,
C) 16 g of methane, C
D) 38 g of fluorine,
Answer:
Success in science is mainly linked to emphasis on
A) experiments.
B) luck.
C) trial and error.
D) philosophical discussions.
Answer:
Life forms in the Precambrian include
A) trilobites, brachiopods and stromatolites.
B) cyanobacteria and trilobites.
C) the agnatha and the coelacanths.
D) stromatolites and certain primitive blue-green algae.
Answer:
As sediments accumulate, compaction and cementation produce sedimentary rock. This
process is called
A) consolidation.
B) solidification.
C) lithification.
D) solifluction.
Answer:
Damage from an earthquake is most severe when the
A) epicenter is close to the surface.
B) surface material is composed of unconsolidated sediments.
C) buildings and structures are poorly constructed.
D) all of the above
Answer:
The most noteworthy event that occurred during the Pleistocene was the
A) emergence of the early humans.
B) ice age.
C) appearance of the grasslands.
D) divergence of horses.
Answer:
If a nucleus of Th absorbs a neutron and the resulting nucleus undergoes two
successive beta decays (emitting electrons), what nucleus results?
A) Americium-232
B) Plutonium-232
C) Thorium-233
D) Uranium-233
Answer:
Which should be larger, the potassium atom, K, or the potassium ion, K ?⁺
A) The potassium ion, K is larger since charging an atom always makes it larger.⁺
B) The potassium atom, K, with an additional shell of electrons is larger.
C) The potassium ion, K is larger since it has an extra electron which increases its size.⁺
D) The potassium atom and the potassium ion are exactly the same size and only differ
in charge.
Answer:
The probe tip of a scanning probe microscope
A) floats above the atoms of a sample.
B) etches into the atoms of a sample.
C) chemically changes the atoms of a sample.
D) injects a magnetic field into the atoms of a sample.
Answer:
If an element has 15 protons and 16 neutrons and 15 electrons, what is the mass number
of the element?
A) 31
B) 15
C) 16
D) 30
E) none of the above
Answer:
Glass is transparent to light of frequencies that
A) match its natural frequencies.
B) are below its natural frequencies.
C) both of these
D) none of the above
Answer:
Two life preservers have identical volumes, one filled with Styrofoam and the other
filled with sand. When both are fully submerged, the buoyant force is greater on the one
filled with
A) Styrofoam.
B) sand.
C) same on each if volumes remain the same.
Answer:
The speed of a seismic wave depends on
A) the type of material it travels through.
B) how far it has to travel.
C) its amplitude.
D) its frequency.
Answer:
Heat is thermal energy that flows from
A) hot to cold.
B) high energy to low energy.
C) high thermal pressure to low thermal pressure.
D) all of the above
Answer:
The ionosphere
A) is produced by the action of solar radiation and atmospheric atoms.
B) consists of ozone ions.
C) reflects solar ultraviolet and atmospheric atoms.
D) occurs at roughly the same altitude as high clouds.
Answer:
What would the concentration of H3O+ be if the concentration of OH– was 1 10-1M?
[H3O+] [OH–] = Kw = 1 10-14
A) 1 10-3
B) 1 10-2
C) 1 10-4
D) 1 1013
E) none of the above
Answer:
How many electrons are gained or lost in the following half-reaction?
Zn → Zn+2
A) 2 electrons are lost
B) 1/2 electron is gained
C) 1/2 electron is lost
D) 2 electrons are gained
E) 4 electrons are gained
Answer:
The principle of faunal succession states that
A) fossil organisms follow one another in a definite, irreversible time sequence.
B) rock cycling may dislodge and relocate fossils, making their age difficult to
determine.
C) fossils are always older than the rock in which they are found.
D) fossils are ordained.
Answer:
Small openings between leaves in a tree act as pinholes. The round spots of light cast on
the ground below are images of
A) the Sun.
B) the openings themselves.
C) both of these
D) neither of these
Answer:
What element is oxidized in the following equation and what element is reduced?
+ 2 Ag → Sn + 2 Ag⁺
A) The tin ion, , is oxidized, while the silver, Ag, is reduced.
B) The tin ion, , is reduced, while the silver, Ag, is oxidized.
C) Both the tin ion, , and the silver, Ag, are reduced.
D) Both the tin ion, , and the silver, Ag, are oxidized.
Answer:
Alkaloid salts are not very soluble in the organic solvent diethyl ether. What might
happen to the free-base form of caffeine dissolved in diethyl ether if gaseous hydrogen
chloride, HCl, were bubbled into the solution?
A) A second layer of water would form.
B) Nothing, and the HCl gas would merely bubble out of solution.
C) The diethyl ether insoluble caffeine salt would form as a white precipitate.
D) The acid/base reaction would release heat, which would cause the diethyl ether to
start evaporating.
Answer:
If the relative mass of a hydrogen atom is 1/4 that of a helium atom, how many helium
atoms would you need to equal the mass of 200 hydrogen atoms?
A) 50
B) 200
C) 800
D) 4
E) 100
Answer:
An atom loses an electron to another atom. Is this an example of a physical or chemical
change?
A) physical change involving the formation of negative ions
B) chemical change involving the formation of neutral atoms
C) physical change involving the formation of positive ions
D) chemical change involving the formation of ions
Answer:
An Earth satellite in an elliptical orbit travels fastest when it is
A) nearest the Earth.
B) farthest from the Earth.
C) neither of these
Answer:
For the following acid-base reaction, identify what is formed in the space marked.
H2SO4 + KOH KHSO⇌4 + ???
A) K2SO4
B) H3OSO4
C) H2O
D) KOH2SO4
E) none of the above
Answer:
A mass on the end of a spring bobs up and down 1 complete cycle every 2 s. Its
frequency is
A) 0.5 Hz.
B) 2 Hz.
C) neither of these
Answer:
A magnetic force acts most strongly on a current carrying wire when it
A) carries a very large current.
B) is perpendicular to the magnetic field.
C) either or both of these
D) none of the above
Answer:
Compared to the resistance of two resistors connected in series, the same two resistors
connected in parallel have
A) more resistance.
B) less resistance.
C) the same resistance.
Answer:
Just as a sustained flow of water in a hydraulic circuit needs a pump, the flow of charge
in an electric circuit needs
A) current.
B) voltage.
C) resistance.
Answer:
The following set of redox reactions takes place as shown.
Container A Container B
Fe → Fe+2 + 2e- Cu+2 + 2e- → Cu
If you had two containers filled with the ion solution described above with only a wire
connecting a piece of iron (in container A) and a piece of copper (in container B), which
way do the electrons flow?
A) There is no continuous flow of electrons.
B) The electrons from from container A to container B.
C) The electrons flow from container B to container A.
D) The electrons flow back and forth between the two containers.
E) The electrons only move in the containers they originate in.
Answer:
If an element has 9 protons and 10 neutrons and 9 electrons, which expression correctly
identifies the element?
A) F
B) F
C) K
D) K
E) K
Answer:
How would you classify the following material?
coffee (with milk)
A) a suspension
B) a heterogeneous mixture
C) a solution
D) an element
E) a compound
Answer:
Is the rate of Earth’s rotation increasing or decreasing?
A) It is increasing.
B) It is decreasing.
C) It is remaining relatively steady.
D) It is increasing and decreasing in cyclic fashion.
Answer: