| Questions |
Answers |
Explanation |
| 21. Which type of reaction occurs when
nonmetal atoms become negative nonmetal ions?
A. oxidation
B. reduction
C. substitution
D. condensation
|
B |
reduction the
oxidation number (charge) becomes negative, it decreases
or reduces |
22. Given the reaction:
Once equilibrium is reached, which statement is
accurate?
A. The concentration of Ag+(aq) is greater than the
concentration of Cl–(aq).
B. The AgCl(s) will be completely consumed.
C. The rates of the forward and reverse reactions are
equal.
D. The entropy of the forward reaction will continue to
decrease.
|
C |
ALWAYS ON REGENTS
equilibrium rates are
equal
concentrations constant |
| 23. Which structural formula correctly
represents a hydrocarbon molecule?
A.
B.
C.
D.
|
B |
carbon must have 4
bonds
H has 1
O has 2 |
24. Given the structural formulas for two
organic compounds:
The differences in their physical and chemical
properties are primarily due to their
different
A. number of carbon atoms
B. number of hydrogen atoms
C. molecular masses
D. functional groups
|
D |
the functional
groups are different |
| 25. Which structural formula represents a
molecule that is not an isomer of pentane?
A.
B.
C.
D.
|
D |
isomers same formula
different structure
Note A is pentane, not an
isomer of |
| 26. The bonds in the compound MgSO4 can be
described as
A. ionic, only
B. covalent, only
C. both ionic and covalent
D. neither ionic nor covalent
|
C |
SO4 2- (sulfate is
covalent)
MgSO4 is ionic
so there is both |
| 27. Given the reaction:
Which statement correctly describes what occurs when
this reaction takes place in a closed system?
A. Atoms of Zn(s) lose electrons and are oxidized.
B. Atoms of Zn(s) gain electrons and are reduced.
C. There is a net loss of mass.
D. There is a net gain of mass.
|
A |
the Zn becomes Zn+2
charge went up...oxidation
it is oxidized by losing
electrons
LEO GER |
| 28. When the pH of a solution changes from
a pH of 5 to a pH of 3, the hydronium ion concentration
is
A. 0.01 of the original content
B. 0.1 of the original content
C. 10 times the original content
D. 100 times the original content
|
D |
each pH unit change
is 10 times more concentrated in H3O+
5 to 3 is 100 times more H3O+ |
| 29. A sample of Ca(OH)2 is considered to
be an Arrhenius base because it dissolves in water to
yield
A. Ca2+ ions as the only positive ions in
solution
B. H3O+ ions as the only positive
ions in solution
C. OH– ions as the only negative ions in
solution
D. H– ions as the only negative ions in
solution
|
C |
Base hydroxide ions
acids hydronium or hydrogen
ions |
| 30. Which reaction occurs when hydrogen
ions react with hydroxide ions to form water?
A. substitution
B. saponification
C. ionization
D. neutralization
|
D |
hydogen and
hydroxide making water
neutralization |