| Questions |
Answers |
Explanations |
|
41 Based on intermolecular forces, which
of these substances
would have the highest boiling point?
(1)
He (3) CH 4
(2) O 2
(4) NH3
|
4 |
NH3 is
the only polar molecules
the others are nonpolar |
|
42 How much heat energy must be absorbed
to completely
melt 35.0 grams of H2O(s)
at 0°C?
(1) 9.54
J (3) 11
700 J
(2) 146
J
(4) 79 100 J |
3 |
q=mHf
q=35g x 334J/g |
|
43 The graph below represents the
uniform heating of
a substance, starting below its melting point, when
the substance is solid.
Which line segments represent an
increase in average
kinetic energy?
(1) AB
and BC
(3) BC
and
DE
(2) and AB
CD
(4) DE
and EF |
2 |
Temperature
is Average Kinetic Energy
increasing KE occurs in the
diagonal segments |
| 44
Given the three organic structural formulas shown below:
Which organic-compound classes are
represented by these structural formulas, as shown from
left to right?
(1) ester, organic acid, ketone
(2) ester, aldehyde, organic acid
(3) ketone,
aldehyde, alcohol
(4) ketone,
organic acid, alcohol |
4 |
Use
table R |
|
45 Given the reaction at equilibrium:
N 2(g)
+ O2(g)
+ energy <--> 2 NO(g)
Which change will result in a decrease
in the
amount of NO(g)
formed?
(1) decreasing the pressure
(2) decreasing the concentration of N 2(g)
(3) increasing the concentration of O 2(g)
(4) increasing the temperature
|
2 |
since
the moles of gases are the same pressure changes do
nothing
raising the temperature is
adding energy and will shift the equilibrium right thus
increasing NO |
|
46 Given the equation:
X +
Cl2 -->
C2H5Cl
+ HCl
Which molecule is represented by X?
(1) C 2H4
(3) C3H6
(2) C 2H6
(4) C3H8
|
2 |
find the
missing piece |
|
47 Which metal reacts spontaneously with
a solution containing
zinc ions?
(1)
magnesium
(3) copper
(2)
nickel
(4) silver |
1 |
Table J
above zinc |
|
48 Which statement correctly describes a
solution with
a pH of 9?
(1) It has a higher concentration of H 3O+
than OH–
and causes
litmus to turn blue.
(2) It has a higher concentration of OH –
than H3O+
and
causes litmus to turn blue.
(3) It has a higher concentration of H 3O+
than OH–
and causes
methyl orange to turn yellow.
(4) It has a higher concentration of OH –
than H3O+
and causes
methyl orange to turn red. |
2 |
pH of 9
is basic so OH- has a larger concentration
than H3O+
litmus is blue in a base using
Table M
acid-bases |
|
49 How many days are required for 200.
grams of radon-222
to decay to 50.0 grams?
(1) 1.91
days (3)
7.64 days
(2) 3.82
days (4)
11.5 days |
3 |
200->100->50
2 (1/2 lives)
2 x 3.82d per half life |
|
50 A student calculates the density of
an unknown solid.
The mass is 10.04 grams, and the volume is 8.21
cubic centimeters. How many significant figures should
appear in the final answer?
(1)
1 (3) 3
(2)
2 (4) 4 |
3 |
since
division is involved, the answer is only as precise as
the least precise measurement, which is 8.21 so the
answer has 3 sig figs |