AnswersTX-Chemistry B-CRLab: Measuring pH

Lab: Measuring pH — Cumulative exam Answers

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The diagram below shows the movement of particles.What does this piece of evidence best support?

Question illustration
A
the collision theory
B
the Maxwell-Boltzmann distribution
C
the effect of pressure on reaction rates
D
the effect of temperature on reaction rates
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The pH of a solution is 2.0. Which statement is correct?Useful formulas include , , , and .

Question illustration
A
The pOH of the solution is 12.0.
B
The concentration of OH– ions is 1.0 10–2 M.
Option B
C
The concentration of ions is 100.0 M.
Option C
D
The pOH of the solution is 16.0.
63

The electron configuration for magnesium is shown below.1s22s22p63s2Which diagram shows the correct distribution of electrons in the electron shells of a magnesium atom?

A
A gray circle labeled 3 P 4 N is surrounded by two concentric circles. The inner circle has gray dots at the north and south positions, and the outer circle has a dot at the north position.
Option A
B
A gray circle labeled 4 P 5 N is surrounded by two concentric circles. Each of the concentric circles has gray dots at the north and south positions.
Option B
C
A gray circle labeled 12 P 12 N is surrounded by three concentric circles. The innermost circle has gray dots at the north and south positions; the middle circle has eight gray dots equally spaced around the circle, with dots aligned with those in the inner circle; the outer circle has gray dots at the north and south positions.
Option C
D
A gray circle labeled 12 P 12 N is surrounded by three concentric circles. The innermost circle has gray dots at the north and south positions; the middle circle has eight gray dots equally spaced around the circle, with dots aligned with those in the inner circle; the outer circle has a gray dot at the north position.
Option D
64

A particle that travels around the nucleus of an atom in orbitals is called a(n)

A
quark.
B
proton.
C
neutron.
D
electron.
65

Who wrote the first modern chemical textbook?

A
Antoine Lavoisier
B
Dmitri Mendeleev
C
Henry Moseley
D
Johann Dobereiner
66

It is easier to determine the electron configurations for the p-block elements in periods 1, 2, and 3 than to determine the electron configurations for the rest of the p-block elements in the periodic table because

A
they have a larger number of core electrons.
B
their electrons are assigned to s and p orbitals only.
C
their electrons are placed in a higher number of orbitals.
D
they have more valence electrons available for bonding.
67

Which element does the electron configuration 1s22s22p2 represent?

A
B
B
C
C
N
D
K
68

A solid compound in a sealed container was kept at a very low temperature in a freezer. When placed at room temperature, the substance quickly turned into a liquid. This compound is most likely which of the following?

A
an ionic compound because it has a low boiling point
B
a covalent compound because it has a low boiling point
C
an ionic compound because it has a low melting point
D
a covalent compound because it has a low melting point
69

Which of these acids occurs naturally in the body and performs important regulatory functions?

A
carbonic acid
B
acetic acid
C
magnesium hydroxide
D
sodium hydroxide
70

Some atoms are exceptions to the octet rule by having an expanded octet. Which characteristic is needed for an atom to have an expanded octet?

A
The atom has empty d-orbitals.
B
The atom has more than eight valence electrons before bonding.
C
The atom has empty p-orbitals.
D
The atom has fewer than eight valence electrons after bonding.
71

Which property best indicates that a compound contains an ionic bond?

A
It is insoluble in water.
B
It can be easily flattened.
C
It has a low boiling point.
D
It conducts electricity when molten.
72

Which applies to the collision theory?

A
Particles need to collide in order to react.
B
Particles may obtain successful collisions in any molecular orientation.
C
Temperature increase causes kinetic energy of particles to decrease.
D
Reactions do not have to begin with collision of molecules or particles.

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