41 Based on intermolecular forces, which
of these substances
would have the highest boiling point?
He (3) CH4
the only polar molecules
the others are nonpolar
42 How much heat energy must be absorbed
melt 35.0 grams of H2O(s)
J (3) 11
(4) 79 100 J
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
(2) and AB
is Average Kinetic Energy
increasing KE occurs in the
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
organic acid, alcohol
45 Given the reaction at equilibrium:
+ energy <--> 2 NO(g)
Which change will result in a decrease
amount of NO(g)
(1) decreasing the pressure
(2) decreasing the concentration of N2(g)
(3) increasing the concentration of O2(g)
(4) increasing the temperature
the moles of gases are the same pressure changes do
raising the temperature is
adding energy and will shift the equilibrium right thus
46 Given the equation:
Which molecule is represented by X?
47 Which metal reacts spontaneously with
a solution containing
48 Which statement correctly describes a
a pH of 9?
(1) It has a higher concentration of H3O+
litmus to turn blue.
(2) It has a higher concentration of OH–
causes litmus to turn blue.
(3) It has a higher concentration of H3O+
methyl orange to turn yellow.
(4) It has a higher concentration of OH–
methyl orange to turn red.
||pH of 9
is basic so OH- has a larger concentration
litmus is blue in a base using
49 How many days are required for 200.
grams of radon-222
to decay to 50.0 grams?
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 (3) 3
2 (4) 4
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