MC_Chem1A_Sp08_LabQuiz3

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____	1.	If 46.1 g Zn at 18.0 °C is placed in 80.0 g H2O at 75.0 °C, what is the final temperature of the mixture? The specific heat capacities of zinc and water are 0.388 J/g·K and 4.184 J/g·K, respectively.
a.	20.9 °C	
b.	27.3 °C	
c.	64.5 °C	
d.	65.7 °C	
e.	72.1 °C	

____	2.	Specific heat capacity is
a.	the quantity of heat needed to change 1.00 g of a substance by 1.00 K.	
b.	the mass of a substance that 1.00 J of energy will heat by 1.00 K.	
c.	the mass of a substance that 1.00 cal of energy will heat by 1.00 K.	
d.	the temperature change undergone when 1.00 g of a substance absorbs 4.184 J.	
e.	the quantity of heat required to melt 4.184 g of a substance.	

____	3.	What is the expected number of valence electrons for an atom of a group 6A element?
a.	0	
b.	1	
c.	2	
d.	4	
e.	6	

____	4.	What is the total number of valence electrons in a carbon dioxide molecule?
a.	4	
b.	8	
c.	16	
d.	20	
e.	22	

____	5.	What is the correct Lewis structure for IF3?

a.	1	
b.	2	
c.	3	
d.	4	
e.	5	

____	6.	Use VSEPR theory to predict the molecular geometry of H3O+.
a.	trigonal-pyramidal	
b.	trigonal-planar	
c.	bent	
d.	T-shaped	
e.	linear	

____	7.	What are the Cl-P-Cl bond angles in PCl3?
a.	109.5°	
b.	120°	
c.	109.5° and 120°	
d.	90° and 120°	
e.	90° and 180°	

____	8.	Which one of the following molecules has a dipole moment?
a.	CI4	
b.	PF5	
c.	NCl3	
d.	SO3	
e.	O2	

____	9.	At 0.984 atm, the height of mercury in a barometer is 74.8 cm. If the mercury were replaced with water, what height of water (in centimeters) would be supported at this pressure? The densities of Hg and H2O are 13.5 g/cm3 and 1.00 g/cm3, respectively.
a.	5.54 cm	
b.	13.3 cm	
c.	994 cm	
d.	1.01 ´ 103 cm	
e.	1.84 ´ 105 cm	

____	10.	A balloon is filled with He gas to a volume of 3.22 L at 32 °C. The balloon is placed in liquid nitrogen until its temperature reaches -132 °C. Assuming the pressure remains constant, what is the volume of the cooled balloon?
a.	0.628 L	
b.	0.781 L	
c.	1.24 L	
d.	1.49 L	
e.	6.96 L	

____	11.	Which of the following relationships are true for gases?

1.	The number of moles of a gas is directly proportional to its volume (at constant pressure).	
2.	The pressure of a gas is inversely proportional to its temperature in Kelvins (at constant volume).	
3.	The volume of a gas is directly proportional to its pressure (at constant temperature).	

a.	1 only	
b.	2 only	
c.	3 only	
d.	1 and 2	
e.	2 and 3	

____	12.	DH for dissolving CaCl2 in water is -81.3 kJ/mol. Predict the final temperature if 0.20mol CaCl2 is dissolved in 200.0 mL water at 20°C. Specific heat of water is 4.18 J/(g.°C).
a.	29.7°C	b.	9.7°C	c.	19.7°C	d.	39.4°C	

____	13.	When a salt is dissolves endothermically in water, which attractive forces are stronger?

a.	Forces between the ions of the salt	b.	Forces between the ions and the water molecules.	c.	Both the choices (a) and (b).	d.	None of the choices (a) or (b).	

____	14.	Which of the following colors of visible light has the longest wavelength?
a.	orange	
b.	blue	
c.	red	
d.	green	
e.	yellow	

____	15.	An argon ion laser emits light at 488 nm. What is the frequency of this radiation?
a.	4.07 ´ 10-19 s-1	
b.	1.63 ´ 10-15 s-1	
c.	1.46 ´ 102 s-1	
d.	2.05 ´ 106 s-1	
e.	6.14 ´ 1014 s-1	

____	16.	Excited hydrogen atoms emit light in the ultraviolet at 2.47 ´ 1015 Hz. What is the energy of a single photon with this frequency?
a.	8.04 ´ 10-41 J	
b.	2.68 ´ 10-19 J	
c.	1.64 ´ 10-18 J	
d.	6.11 ´ 10-17 J	
e.	1.21 ´ 10-7 J	

____	17.	According to the Bohr model for the hydrogen atom, the energy necessary to excite an electron from n = 2 to n = 3 is ____ the energy necessary to excite an electron from n = 4 to n = 5.
a.	less than	
b.	greater than	
c.	equal to	
d.	either equal to or greater than	
e.	either less than or equal to	

____	18.	If a hydrogen atom in the excited n = 3 state relaxes to the ground state, what is the maximum number of possible emission lines?
a.	0	
b.	1	
c.	2	
d.	3	
e.	infinite	

MC_Chem1A_Sp08_LabQuiz3
Answer Section

MULTIPLE CHOICE

	1.	ANS:	E	PTS:	1	OBJ:	6.2 Specific Heat Capacity and Heat Transfer

	2.	ANS:	A	PTS:	1	OBJ:	6.2 Specific Heat Capacity and Heat Transfer

	3.	ANS:	E	PTS:	1	OBJ:	9.1 Valence Electrons	

	4.	ANS:	C	PTS:	1	OBJ:	9.4 Covalent Bonding and Lewis Structures

	5.	ANS:	B	PTS:	1	OBJ:	9.6 Exceptions to the Octet Rule

	6.	ANS:	A	PTS:	1	OBJ:	9.7 Molecular Shapes	

	7.	ANS:	A	PTS:	1	OBJ:	9.7 Molecular Shapes	

	8.	ANS:	C	PTS:	1	OBJ:	9.9 Molecular Polarity

	9.	ANS:	D	PTS:	1	OBJ:	12.1 The Properties of Gases

	10.	ANS:	D	PTS:	1	OBJ:	12.2 Gas Laws: The Experimental Basis

	11.	ANS:	A	PTS:	1	OBJ:	12.2 Gas Laws: The Experimental Basis

	12.	ANS:	D
(200g).(4.18J/g.°C).(Tf-20°C) = (0.2 mol CaCl2). (81.3KJ/mol CaCl2). (1000J/1KJ)

PTS:	1

	13.	ANS:	A
Energy needs to be put to separate the ions. This must be higher than the energy liberated when the ions hydrate with water molecules so that the net is energy absorption. Thus endothermic.

PTS:	1

	14.	ANS:	C	PTS:	1	OBJ:	7.1 Electromagnetic Radiation

	15.	ANS:	E	PTS:	1	OBJ:	7.1 Electromagnetic Radiation

	16.	ANS:	C	PTS:	1	OBJ:	7.2 Planck | Einstein | Energy | and Photons

	17.	ANS:	B	PTS:	1	OBJ:	7.3 Atomic Line Spectra and Niels Bohr

	18.	ANS:	D	PTS:	1	OBJ:	7.3 Atomic Line Spectra and Niels Bohr