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Two students independently determine the volume of water delivered by a 10.00-mL
pipet. Each student takes 8 measurements, then computes the average volume delivered
and the standard deviation. The results are tabulated below.
Average St. Dev.
Student A 10.4 mL 0.7 mL
Student B 10.00 mL 0.02 mL
Which statement best describes the results?
A.A: good precision, good accuracy. B: good precision, good accuracy.
B.A: good precision, poor accuracy. B: poor precision, good accuracy.
C.A: poor precision, good accuracy. B: good precision, poor accuracy.
D.A: poor precision, poor accuracy. B: good precision, good accuracy.
E.A: poor precision, poor accuracy. B: poor precision, poor accuracy.
If 27.9 g LiCl is dissolved in 175 g H2O, what is the weight percent of LiCl in the
solution?
A.0.376%
B.6.78%
C.13.8%
D.15.9%
E.19.0%
One kind of battery used in watches contains mercury(II) oxide. As current flows, the
mercury(II) oxide is reduced to mercury.
HgO(s) + H2O( ) + 2 e" Hg( ) + 2 OH"(aq)
If 2.3 10"5 amperes flows continuously for 1200 days, what mass of Hg( ) is produced?
A.2.5 g
B.5.0 g
C.9.9 g
D.13 g
E.15 g
In which group of the following groups of the periodic table are all the elements
nonmetals?
A.2A
B.3A
C.5A
D.6A
E.7A
When heated, azomethane decomposes into nitrogen gas and ethane gas.
CH3N=NCH3(g) N2(g) + C2H6(g)
Bond Bond Enthalpy (kJ/molrxn) Bond Bond Enthalpy (kJ/molrxn)
C-H 413 N-N 163
C-N 305 N=N 418
C-C 346 NN 945
Using average bond energies, calculate the enthalpy of reaction.
A."611 kJ
B."527 kJ
C."429 kJ
D."313 kJ
E."263 kJ
All of the following species behave as Lewis acids EXCEPT ____.
A.BH3
B.Al3+
C.SO2
D.Al(OH)3
E.NH3
In positron emission tomography (PET), a positron emitted from an unstable isotope
travels a short distance before it is annihilated by
A.an electron, creating a proton that is detected by the instrument.
B.a neutron, creating two gamma rays that travel in opposite directions.
C.an electron, creating two gamma rays that travel in opposite directions.
D.an alpha particle, creating two protons that travel in opposite directions.
E.gamma ray, creating an electron that is detected by the instrument.
Which one of the following sets of quantum numbers is NOT allowed?
A.n = 7, = 0, = 0, ms = +1/2
B.n = 5, = 3, = "2, ms = +1/2
C.n = 4, = 2, = 0, ms = "1/2
D.n = 3, = 1, = "1, ms = +1/2
E.n = 2, = 1, = 0, ms = 0
The following electrochemical cell has a potential of +0.326 V at 25 C.
Pt | H2(g, 1.00 atm) | H+(aq, 1.00 M) || Cl"(aq) | AgCl(s) | Ag
The standard reduction potential,E, of AgCl(s) = +0.222 V. What is the Cl"(aq)
concentration?
A.1.9 10"19 M
B.5.5 10"10 M
C.0.018 M
D.1.03 M
E.1.8 109 M
What is the weight percent of acetic acid in 7.23 m CH3CO2H(aq)?
A.0.718%
B.7.17%
C.11.5%
D.30.3%
E.42.4%
Which of the following chemical equations corresponds to the standard molar enthalpy
of formation of Na2CO3(s)?
A.2 Na(s) + C(s) + 3 O(g) Na2CO3(s)
B.Na2O(s) + CO2(g) Na2CO3(s)
C.Na2(s) + C(s) + 3 O(g) Na2CO3(s)
D.Na2O2(s) + CO(g) Na2CO3(s)
E.2 Na(s) + C(s) + 3/2 O2(g) Na2CO3(s)
How many moles of HCl must be added to 1.0 L of 1.0 M NH3(aq) to make a buffer
with a pH of 9.00? (pKa of NH4
+ = 9.25)
A.0.36 mol
B.0.44 mol
C.0.56 mol
D.0.64 mol
E.1.8 mol
Calculate the lattice energy of NaBr(s), given the following thermochemical equations,
where DIE and DEA are ionization energy and electron affinity, respectively.
Na(s) Na(g) DfH = +107 kJ
Na(g) Na+(g) + e" DIE = +496 kJ
1/2 Br2(g) Br(g) DfH = +112 kJ
Br(g) + e" Br"(g) DEA = "325 kJ
Na(s) + 1/2 Br2(g) NaBr(s) DfH = "361 kJ
A."963 kJ
B."751 kJ
C."290 kJ
D.+290 kJ
E.+1403 kJ
Which of the underlined atoms (C1, C2, N, and O) are sp2 hybridized?
A.C1 and C2
B.C1, N, and O
C.N and O
D.O and C2
E.O only
If a chemical reaction occurs in a direction that has a positive change in entropy then
A.the change in enthalpy must be negative.
B.the reaction must be spontaneous.
C.heat goes from the system into the surroundings.
D.the reaction must be exothermic.
E.the disorder of the system increases.
What is the hybridization of the central sulfur atom in sulfur dioxide, SO2?
A.sp
B.sp2
C.sp3
D.sp3d
E.sp3d2
What is the correct name for N2O4?
A.nitrogen oxide
B.dinitrogen tetraoxide
C.nitrogen(II) oxide
D.nitrogen tetraoxide
E.dinitrogen tetraoxygen
What is the correct answer to the following expression?
7.4576 10"2 + 4.11 10"5 + 6 10"4 =
A.7. 10"2
B.7.5 10"2
C.7.52 10"2
D.7.522 10"2
E.7.5217 10"2
What mass of Zn(NO3)2 must be diluted to a mass of 1.00 kg with H2O to prepare 97
ppm Zn2+(aq)?
A.7.8 10"6 g
B.7.8 10"3 g
C.3.3 10"2 g
D.1.3 10"1 g
E.2.8 10"1 g
Which of the following chemical equations depicts an alkylation reaction?
A.C6H6( ) + CH3Cl( ) C6H5CH3( ) + HCl(g)
B.2 CH3OH( ) + 3 O2(g) 2 CO2(g) + 4 H2O( )
C.C6H12( ) C6H10( ) + H2(g)
D.CH2ClCH2Cl(g) + H2(g) CH3CH3(g) + Cl2(g)
E.CHClCHCl(g) CH2ClCH2Cl(g)
What is the net ionic equation for the reaction of aqueous sodium hydroxide and
aqueous iron(II) chloride?
A.Na+(aq) + OH"(aq) NaOH(s)
B.Na+(aq) + Cl"(aq) NaCl(s)
C.Fe2+(aq) + 2 OH"(aq) Fe(OH)2(s)
D.Fe2+(aq) + OH"(aq) FeOH+(s)
E.Fe2+(aq) + 2 Cl"(aq) FeCl2(s)
Which species in the reaction below undergoes reduction?
H2O(g) + CO(g) H2(g) + CO2(g)
A.H2O
B.CO
C.H2
D.CO2
E.None
The standard enthalpy of formation of NaOH(s) is "425.9 kJ/mol and the standard
enthalpy of formation of NaOH(aq, 1 m) is "469.2 kJ/mol. Determine the heat of
solution of NaOH. Will the solution temperature increase or decrease when NaOH is
dissolved in water?
A."43.3 kJ/mol; increase
B.+43.3 kJ/mol; increase
C."43.3 kJ/mol; decrease
D.+895.1 kJ/mol; increase
E."895.1 kJ/mol; decrease
What percentage of the world's electricity is supplied by nuclear fusion reactors?
A.0%
B.3%
C.8%
D.17%
E.39%
A mass of 0.4113 g of an unknown acid, HA, is titrated with NaOH. If the acid reacts
with 28.10 mL of 0.1055 M NaOH(aq), what is the molar mass of the acid?
A.2.965 10"3 g/mol
B.9.128 g/mol
C.138.7 g/mol
D.337.3 g/mol
E.820.7 g/mol
What is the energy of a photon with a frequency of 1.09 1015 s"1?
A.6.08 10"49 J
B.1.82 10"40 J
C.7.22 10"19 J
D.2.75 10"7 J
E.2.75 102 J
Which equation depicts hydrogen phosphate ion behaving as a Brnsted-Lowry base in
water?
A.HPO4
2"(aq) + H2O( ) H2PO4
"(aq) + OH"(aq)
B.HPO4
2"(aq) + OH"(aq) PO4
3"(aq) + H2O( )
C.HPO4
2"(aq) + H2O( ) PO4
3"(aq) + H3O+(aq)
D.2 HPO4
2"(aq) + O2"(aq) PO4
3"(aq) + H2O( )
E.2 HPO4
2"(aq) + H2O( ) 2 H2O( ) + P2O7(s)
Which one of the following molecules has a chiral center?
A.
B.
C.
D.
E.
Which of the following statements is/are CORRECT?
1/ The atomic radii of transition metals decrease initially, then increase as one moves
from left to right across a period of the periodic table.
2/ The atomic radii of the d-block elements in the 5th and 6th periods in each group are
almost identical.
3/ The densities of the 6th period transition metals are greater than those of either the 4th
or 5th period transition metals.
A.1 only
B.2 only
C.3 only
D.1 and 2
E.1, 2, and 3
The decomposition of phosphine, PH3, follows first-order kinetics.
4 PH3(g) P4(g) + 6 H2(g)
The half-life for the reaction at 550 C is 81.3 seconds. What percentage of phosphine
remains after 195 seconds?
A.2.2%
B.9.8%
C.19%
D.42%
E.58%
A red laser pointer emits light at a wavelength of 488 nm. If the laser emits 7.5 10"4 J of
energy per second in the form of visible radiation, how many photons per second are
emitted from the laser?
A.4.1 10"19 photons/sec
B.5.4 10"16 photons/sec
C.8.9 1014 photons/sec
D.1.8 1015 photons/sec
E.2.5 1018 photons/sec
In which of the following compounds does the oxidation number of the nitrogen
atom(s) equal +3?
A.NH3
B.N2O4
C.N2H4
D.N2O
E.N2O3
For a given reaction, the activation energy is 63.9 kJ/mol. If the reaction rate constant is
4.1 10"3 M"1s"1 at 32.0 C, what is the reaction rate constant at "5.0 C? (R = 8.314
J/Kmol)
A.1.2 10"3 M"1s"1
B.1.4 10"6 M"1s"1
C.1.3 10"4 M"1s"1
D.4.0 10"3 M"1s"1
E.1.3 10"1 M"1s"1
