A sample of phosphorus-32 is found to have an activity of 885 disintegrations per hour
(dph). After 25 hours the activity has decreased to 841 dph. What is the rate constant for
the decay of phosphorus-32?
A.0.0038 hr“1
B.0.0020 hr“1
C.0.15 hr“1
D.490 hr“1
E.0.12 hr“1
A 1.994 g sample of ethanol, CH3CH2OH, is combusted in a bomb calorimeter. The
temperature of the calorimeter increases by 10.91 K. If the heat capacity of the bomb is
615.5 J/K and it contains 1.150 kg of water, what is the enthalpy change per mole of
ethanol combusted? The specific heat capacity of water is 4.184 J/gK and the molar
mass of ethanol is 46.07 g/mol.
A.”5.921 101 kJ/mol
B.”2.563 103 kJ/mol
C.”1.181 105 kJ/mol
D.”1.368 103 kJ/mol
E.”122.7 103 kJ/mol
Which of the following equations is a correct form of the Nernst equation?
A.
B.
C.
D.
E.
Which of the following statements concerning the Pauli exclusion principle is/are
CORRECT?
1/ If two electrons occupy the same orbital they must have opposite spins.
2/ No two electrons in an atom can have the same four quantum numbers.
3/ Electrons with opposing spins are attracted to each other.
A.1 only
B.2 only
C.3 only
D.1 and 2
E.1, 2, and 3
For which of the following molecules does the carbon atom have sp3 hybridization?
A.Cl2CO
B.CO
C.CS2
D.CH2Cl2
E.HCN
What is the highest oxidation state for chromium?
A.+2
B.+4
C.+6
D.+8
E.+10
A 2.000 g sample of MgCl2xH2O is dried in an oven. When the anhydrous salt is
removed from the oven, its mass is 0.9366 g. What is the value of x?
A.1
B.3
C.6
D.8
E.12
What type of orbital is designated n = 3, = 2, = “2?
A.3s
B.3p
C.3d
D.2f
E.2d
The flexibility, strength, hardness, and malleability of carbon steel is affected by a
heating and cooling process called ____.
A.tempering
B.flotation
C.reduction
D.oxidation
E.recrystallization
The half-life of mercury-203 is 46.6 days. What percentage of mercury-203 remains in
a sample after 365 days?
A.3.72 10-4 %
B.0.439%
C.1.49%
D.5.43%
E.12.8%
Which of the following statements is/are CORRECT?
1/ The angular momentum quantum number, , of an electron in an s orbital is always
equal to 0.
2/ The magnetic quantum number, , of an electron in a p orbital is +1, 0, or “1.
3/ The principle quantum number, n, of an electron in a d orbital must be equal to or
greater than 3.
A.1 only
B.2 only
C.3 only
D.1 and 2
E.1, 2, and 3
All of the following processes lead to an increase in entropy EXCEPT
A.decreasing the volume of a gas.
B.melting a solid.
C.chemical reactions that increase the number of moles of gas.
D.forming mixtures from pure substances.
E.increasing the temperature of a gas.
Rubidium iodide (molar mass 212.4 g/mol) has a face-centered cubic unit cell with
rubidium ions in octahedral holes. If the radius of iodide ion is 219 pm and the density
of RbI is 3.55 g/cm3, what is the radius of the rubidium ion (in pm)?
A.112 pm
B.149 pm
C.181 pm
D.297 pm
E.419 pm
Predict the chemical formula for the bromite ion.
A.Br“
B.BrO4
“
C.BrO3
“
D.BrO2
“
E.BrO“
Which two of the following materials are most likely to be amorphous solids: water,
nylon, glass, potassium nitrate?
A.water and glass
B.nylon and aspirin
C.water and nylon
D.water and aspirin
E.nylon and glass
An ionic compound has the formula MCl2. The mass of 0.3011 mol of the compound is
62.69 grams. What is the identity of the metal?
A.Ni
B.Cu
C.Sn
D.Hg
E.Ba
What is the pH of the buffer that results when 12.0 g of NaH2PO4 and 8.00 g of
Na2HPO4 are diluted with water to a volume of 0.50 L? (Ka of H2PO4
“ = 6.2 10“8, the
molar masses of NaH2PO4 and Na2HPO4 are 120.0 g/mol and 142.0 mol, respectively)
A.4.10
B.6.96
C.7.21
D.7.46
E.9.90
Consider the following half-reactions:
Cl2(g) + 2 e“ 2 Cl“(aq) E = +1.36 V
Ag+(aq) + e“ Ag(s) E = +0.80 V
Cu2+(aq) + 2 e“ Cu(s) E = +0.34 V
Sn2+(aq) + 2 e“ Sn(s) E = “0.14 V
Al3+(aq) + 3 e“ Al(s) E = “1.66 V
Which of the above elements or ions will reduce Cu2+(aq)?
A.Ag(s) and Sn2+(aq)
B.Cl“(aq) and Ag(s)
C.Cl2(g) and Ag+(aq)
D.Sn(s) and Al(s)
E.Sn2+(aq) and Al3+(aq)
The standard enthalpy of formation of RbF(s) is “557.7 kJ/mol and the standard
enthalpy of formation of RbF(aq, 1 m) is “583.8 kJ/mol.Which of the following
statements concerning the dissolution of RbF in water is/are CORRECT?
1/ The dissolution of RbF(s) in water is endothermic.
2/ The standard enthalpy of solution of RbF(s) is +26.1 kJ/mol.
3/ The dissolution of RbF(s) in water results in an increase in the solution’s temperature.
A.1 only
B.2 only
C.3 only
D.1 and 2
E.1, 2, and 3
Which of the following is a correct Lewis structure for PH3?
A.
B.
C.
D.
E.
What is the name given to a substance that increases the rate of a chemical reaction but
is not itself consumed?
A.catalyst
B.reactant
C.intermediate
D.enthalpy
E.rate constant
A 25.0 mL sample of 0.200 M HCO2H(aq) is titrated with 0.100 M KOH(aq). What is
the pH at the equivalence point? (Ka of HCO2H = 1.8 10“4)
A.5.71
B.7.00
C.8.28
D.8.52
E.10.26
Which of the following linear chain alcohols is likely to have the highest standard
entropy in the liquid state?
A.CH3OH
B.CH3CH2OH
C.CH3CH2CH2OH
D.CH3CH2CH2CH2OH
E.CH3CH2CH2CH2CH2OH
How many unit cells share an atom which is located at a corner (or lattice point) of a
unit cell?
A.1
B.2
C.4
D.6
E.8
What mass of iron can be produced from the reaction of 175 kg Fe2O3 with 385 kg CO?
Fe2O3(s) + 3 CO(g) 2 Fe(s) + 3 CO2(g)
A.2.19 kg
B.30.6 kg
C.61.2 kg
D.122 kg
E.512 kg
Which of the following statements is/are CORRECT?
1/ Most ionic compounds containing nitrate ion are soluble in water.
2/ Most ionic compounds containing sulfate ion are insoluble in water.
3/ Most ionic compounds containing carbonate ion are soluble in water.
A.1 only
B.2 only
C.3 only
D.1 and 2
E.1, 2, and 3
Use VSEPR theory to predict the molecular geometry of BrF5.
A.tetrahedral
B.see-saw
C.trigonal-bipyramidal
D.square-pyramidal
E.octahedral
If 0.64 mol PCl5 is placed in a 1.0 L flask and allowed to reach equilibrium at a given
temperature, what is the final concentration of Cl2 in the flask?
PCl5(g) PCl3(aq) + Cl2(g) Kc = 0.47
A.0.20 M
B.0.31 M
C.0.36 M
D.0.55 M
E.0.96 M
Which one of the following complex ions has an optical isomer?
A.[Cu(CN)4]2″
B.[Zn(phen)2]2+
C.[Zn(NH3)2en]2+
D.[Co(H2O)4en]2+
E.[Ni(en)3]2+