Chem 111 Final Exam Practice

A mixture of H2 and O2 is placed in a 6.19 L flask at 15.4 °C. The partial pressure of the H2 is 5.53 atm and the partial pressure of the O2 is 2.02 atm. What is the mole fraction of H2? A. 0.528 B. 0.732 C. 0.268 D. 0.366 E. 1.45

B

A molecule is found to contain 47.35% by mass C, 10.60% by mass H, and 42.05% by mass O. What is the empirical formula for this molecule? A. C4H6O2 B. C3H8O2 C. C3H4O D. C4H8O3 E. C2H6O

B

All of the following are examples of chemical change EXCEPT 1. The condensation of steam. 2. The rusting of iron. 3. The combustion of gasoline. 4. The tarnishing of silver. A. 1 and 2 B. 1 C. 1 and 4 D. 2 and 3 E. 1, 2 and 4

B

Calculate the enthalpy change (ΔrH) for the reaction below, N2(g) + 3 F2(g) → 2 NF3(g) given the bond enthalpies of the reactants and products. Bond Bond Enthalpy (kJ/mol×rxn) N-N 163 N=N 418 N≡N 945 F-F 155 N-F 283 A. -637 kJ B. -288 kJ C. +293 kJ D. +288 kJ E. -1070 kJ

B

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s). For oxygen and fluorine, the σ2p orbital should be lower in energy than the π2p. However, the diagram will still yield correct bond order and magnetic behavior for these molecules. Energy ________ σ*2p ________ ________ π*2p ________ σ2p ________ ________ π2p ________ σ*2s ________ σ2s ________ σ*1s ________ σ1s Refer to Diagram 9-1. According to molecular orbital theory, which of the following species has the highest bond order? A. B22+ B. C22- C. Li2 D. F2 E. F22+

B

How many moles of sodium bromide can be produced from the reaction of 7.42 moles of sodium with 3.84 moles of bromine gas? 2 Na(s) + Br2(g) → 2 NaBr(s) A. 1.86 mol B. 7.42 mol C. 7.69 mol D. 3.84 mol A. 14.8 mol

B

How many sigma (σ) bonds and pi (π) bonds are in carbon dioxide? A. two σ, one π B. two σ, two π C. one σ, two π D. three σ, zero π E. zero σ, three π

B

If 61.2 mL of 2.58 M HCl(aq) is diluted with water to a volume of 973 mL, what is the molarity of the diluted HCl(aq)? A. 1.29 M B. 0.162 M C. 6.16 M D. 41.0 M E. 2.65E-3 M

B

In molecules, as bond order increases, A. both bond length and bond energy increase. B. bond length decreases and bond energy increases. C. bond length increases and bond energy is unchanged. D. both bond length and bond energy decrease. E. bond length is unchanged and bond energy increases.

B

Non-ideal behavior for a gas is most likely to be observed under conditions of A. high temperature and high pressure. B. low temperature and high pressure. C. high temperature and low pressure. D. low temperature and low pressure. E. standard temperature and pressure.

B

What is the correct chemical name for the compound Na2O? A. disodium monoxide B. sodium oxide C. sodium peroxide D. disodium oxide E. sodium monoxide

B

Which have the same number of unpaired electrons as Ni2+? 1.) Ti 2.) Mn3+ A. 1 and 2 B. 1 only C. 2 only D. Neither

B

Which molecule would you predict to have the strongest C-C bond? A. C2Cl6 B. C2Cl2 C. All have about the same C-C bond strength. D. C2Cl4

B

Which of the following atoms is diamagnetic in the ground electronic state? A. S B. Sr C. Mn D. Ge E. I

B

Which of the following is the smallest mass? A. 3.48E+9 pg B. 1.86E-5 g C. 0.227 mg D. 2.43E+7 ng E. 1.57E+6 ng

B

Which species in the below reaction is the reducing agent? A. 2Al(s)+ 3 Cl2(g)2AlCl3(s) B. Cl2(g) C. Al(s) D. The above reaction is not a redox reaction. E. AlCl3(s)

B

Which term best describes methane, CH4? A. atom B. chemical compound C. ion D. element E. homogeneous mixture

B

Arrange P, Na, Cl, and Mg in order of increasing first ionization energy. A. Mg < Na < Cl < P B. Cl < P < Mg < Na C. Na < Mg < P < Cl D. P < Mg < Cl < Na E. Na < Cl < P < Mg

C

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s). For oxygen and fluorine, the σ2p orbital should be lower in energy than the π2p. However, the diagram will still yield correct bond order and magnetic behavior for these molecules. Energy ________ σ*2p ________ ________ π*2p ________ σ2p ________ ________ π2p ________ σ*2s ________ σ2s ________ σ*1s ________ σ1s Refer to Diagram 9-1. According to molecular orbital theory, which of the following species is least likely to exist (i.e., has the lowest bond order)? A. C22- B. B22- C. H22- D. F22+ E. O22+

C

How many moles of Mg3P2(s) can be produced from the reaction of 0.370 mol Mg(s) with 5.83E-2 mol P4(s)? 6 Mg(s) + P4(s) → 2 Mg3P2(s) A. 0.370 mol B. 2.92E-2 mol C. 0.117 mol D. 5.83E-2 mol E. 0.740 mol

C

How many protons, neutrons and electrons are present in one ion of 31P3-? A. protons = 31, neutrons = 15, electrons = 3 B. protons = 15, neutrons = 31 , electrons = 15 C. protons = 15, neutrons = 16, electrons = 18 D. protons = 15, neutrons = 16, electrons = 12

C

Put the following atoms in order of INCREASING size. sodium, nitrogen, hydrogen, fluorine A. fluorine < nitrogen < hydrogen < sodium B. hydrogen < nitrogen < fluorine < sodium C. hydrogen < fluorine < nitrogen < sodium D. sodium < nitrogen < fluorine < hydrogen E. sodium < fluorine < nitrogen < hydrogen

C

The Arsenic atom (As) has ____ core electrons. A. 18 B. 15 C. 28 D. 3 E. 5

C

The quantum number l tells us: 1. The shape of an orbital. 2. The number of spherical nodes an orbital has. 3. The number of planar nodes an orbital has. A. 3 B. 2 C. 1 and 3 D. 1, 2 and 3 E. 1

C

Use VSEPR Theory to predict the molecular geometry around the central atom in each of the following molecules. Which of the following molecular geometries are correct? 1. NO3-, trigonal pyramidal 2. CN-, linear 3. SO2, bent A. None B. 1 and 3 C. 2 and 3 D. 1 and 2 E. 2 only

C

Use the bond enthalpies tabulated below to estimate the enthalpy of the following reaction. H2(g) + 1/2 O2(g) H2O(g) Bond Enthalpy (kJ/mol) H-H = 436 O-H = 463 O-O = 146 O=O = 498 A. -168 kJ B. -417 kJ C. -241 kJ D. -8 kJ E. +8 kJ

C

What are the spectator ions in the reaction between aqueous hydrobromic acid and aqueous sodium hydroxide? A. H+, Br-, Na+, and OH- B. H+ and OH- C. Na+ and Br- D. Na+ only E. Br- only

C

What is the B-F bond order in BF3? A. 3/2 B. 2 C. 1 D. 1 and 2 E. 4/3

C

What is the mass of 0.104 mol O2? A. 1.66 g B. 3.25E-3 g C. 3.33 g D. 32.0 g E. 308 g

C

What is the net ionic equation for the reaction of iron(III) hydroxide and hydrochloric acid? A. 3HCl(aq)+Fe(OH)3(aq)3H2O(l)+FeCl3(aq) B. H+(aq)+OH-(aq)H2O(l) C. Fe(OH)3(s)+3H+(aq)Fe3+(aq)+3H2O(l) D. Fe(OH)3(aq)+3H+(aq)3H2O(l)+Fe3+(aq) E.OH-(aq)+HCl(aq)H2O(l)+Cl-(aq)

C

What is the percent by weight of carbon in ethane, C2H6? A. 74.35 B. 20.15 C. 79.85 D. 39.93 E. 0.799

C

What type of orbital is designated n = 3, l = 2? A. 3p B. 2p C. 3d D. 3s E. 4d

C

Which have sp2 hybridization on the central atom? 1. NF3 2. SO2 A. Neither B. 1 and 2 C. 2 only D. 1 only

C

Which molecules contain a triple bond? 1. HCN 2. O2 3. N2 A. 3 only B. 2 only C. 1 and 3 D. 1 only E. 2 and 3

C

Which molecules have triple bonds? 1.) HCN 2.) C2Cl2 A. 1 only B. Neither C. 1 and 2 D. 2 only

C

Which of the following are isoelectronic with the sodium ion? 1.) oxide ion 2.) sulfide ion 3.) fluoride ion A. 2 only B. 1 only C. 1 and 3 D. 2 and 3 E. 3 only

C

Which of the following are oxidation-reduction reactions? 1. Zn(s) + CuSO4(aq) ZnSO4(aq) + Cu(s) 2. PbCl2(s) + 2 KI(aq) PbI2(s) + 2 KCl(aq) 3. CaCO3(s) CO2(g) + CaO(s) A. 1 and 3 B. 2 only C. 1 only D. 1 and 2 E. 2 and 3

C

Which of the following chemical equations show oxidation-reduction reactions? 1. Mg(s) + I2(aq) → MgI2(s) 2. Pb(ClO4)2(aq) + 2 KI(aq) → PbI2(s) + 2 KClO4(aq) 3. Fe2O3(s) + 3 CO(g) → 2 Fe(s) + 3 CO2(g) A. 2 only B. 1 and 2 C. 1 and 3 D. 2 and 3 E. 1 only

C

Which of the following is the smallest mass? A. 3.14E+9 pg B. 1.96E+7 ng C. 1.63E-5 g D. 2.25E+6 ng E. 0.316 mg

C

Which of the following observations is/are examples of chemical change? 1. Sodium chloride melts at 801 0C. 2. The density of water decreases when it changes from a liquid to a solid. 3. The combustion of propane gas yields carbon dioxide and water. A. 1 only B. 1 and 2 C. 3 only D. 2 only E. 2 and 3

C

Which one of the following aqueous salts will form a precipitate when added to Pb(CH3COO)2 but will not form a precipitate when added to Zn(CH3COO)2 ? A. KOH B. K2S C. KCl D. K2CO3 E. None

C

Which one of the following molecules is polar? A. BCl3 B. SO3 C. SF4 D. CCl4 E. Br2

C

Which one of the following sets of quantum numbers is NOT allowed? A. n = 3, l = 1, mt = -1, ms = +1/2 B. n = 5, l = 3, mt = -2, ms = +1/2 C. n = 2, l = 1, mt = 0, ms = 0 D. n = 7, l = 0, mt = 0, ms = +1/2 E. n = 4, l = 2, mt = 0, ms = -1/2

C

Which species is reduced in the reaction below? I-(aq) + ClO-(aq) → IO-(aq) + Cl-(aq) A. H2O B. Cl- C. ClO- D. IO- E. I-

C

Write a balanced chemical equation for the combustion of copper to yield copper(I) oxide. A. 2 Cu(s) + O2(g) --> 2 CuO(s) + CO2(g) + H2O(g) B. Cu(s) + O2(g) --> CuO2(s) C. 4 Cu(s) + O2(g) --> 2 Cu2O(s) D. Cu(s) + O(g) --> CuO(s) E. 2 Cu(s) + O(g) --> Cu2O(s) + CO2(g) + H2O(g)

C

You have 3.24 g of each of the following elements: Li, Ca, Fe, S and Cu. Which sample contains the largest number of moles? A. Fe B. Ca C. Li D. Cu E. S

C

Arrange Be, Sr, Mg, and Ca in order of increasing atomic radius. A. Be < Mg < Ca < Sr B. Sr < Ca < Mg < Be C. Ca < Mg < Be < Sr D. Be < Ca < Sr < Mg E. Ca < Sr < Be < Mg

A

Calculate the number of moles of aluminum oxide in 7.49 g Al2O3. A. 7.35E-2 mol B. 0.103 mol C. 764 mol D. 4.90E-2 mol E. 13.6 mol

A

For a hydrogen atom, calculate the wavelength of the photon emitted in the transition from n=4 to n=2. Rydberg constant is 1.097x10+7 m-1. A. 486.2 nm B. 260.5 nm C. 550.4 nm D. 350.0 nm E. 150.2 nm

A

How many GRAMS of copper(II) are present in 4.81 grams of copper(II) sulfide? A. 3.20 B. 0.97 C. 1.61 D. 3.84

A

How many equivalent Lewis structures are needed to describe the bonding in the nitrite ion, NO2? ? What is the average N-O bond order? A. 2, 3/2 B. 1, 2 C. 3, 4/3 D. 3, 3

A

How many significant figures should be reported when the numbers 50.945 and 48.3 are subtracted? How many when they are divided? A. 2, 3 B. 3, 2 C. 3, 3 D. 3, 4 E. 4, 3

A

If a radio wave has a frequency of 259 MHz, what is the wavelength of this radiation? A. 1.16 m B. 1.16E+12 m C. 1.16E+6 m D. 259 m E. 7.76E+10 m

A

In the reaction below, the oxidation state of manganese changes from ____ to ____. Cr + MnO4 - + 2 H2O MnO2 + Cr(OH)3 + OH - A. +7, +4 B. +8, +2 C. -1, 0 D. +6, +2 E. +6, +4

A

Iron rusts according to the following equation: __ iron(s) + __ oxygen(g) __ iron(III) oxide(s) What are the respective coefficients when the equation is balanced with the smallest integer values? A. 4, 3, 2 B. 2, 3, 1 C. 3, 3, 2 D. 1, 1, 1

A

Put the following ions in order of increasing size. A. Al3+ < Na+ < O2- < S2- B. Na+ < Al3+ < O2- < S2- C. O2- < S2- < Al3+ < Na+ D. S2- < O2- < Na+ < Al3+ E. Na+ < Al3+ < S2- < O2-

A

Question 22 Close Window Score: Congratulations, you were awarded all 1 points for your responses. All of the following sets of quantum numbers are allowed EXCEPT A. n = 2, l = 2, mt = +1 B. n = 5, l = 4, mt = -3 C. n = 3, l = 1, mt = -1 D. n = 4, l = 1, mt = 0 E. n = 1, l = 0, mt = 0

A

The radius of an atom is 0.250 nm. What is the radius in millimeters? A. 2.50E-7 mm B. 2.50E+5 mm C. 2.50E-10 mm D. 2.50E+8 mm E. 2.50E-4 mm

A

What are the spectator ions in the reaction between aqueous nitric acid and ammonia? A. NO3- only B. H+, NO3-, and NH4+ C. H+ and NH4+ D. NO3- and NH4+ E. H+ only

A

What is the mass percent of chlorine in magnesium chloride? A. 74.47% B. 40.67% C. 25.53% D. 59.33% E. 37.24%

A

Which molecules have sp3d hybridization? 1. SF4 2. XeF2 A. 1 and 2 B. Neither 1 nor 2 C. 2 only D. 1 only

A

A 23.91 mL sample of NaOH is titrated with 27.28 mL of 0.1749 M HCl(aq). What is the concentration of the NaOH solution? A. 1.996E-4 M B. 0.1749 M C. 1.141E-4 M D. 0.1996 M E. 4.771E-3 M

D

A lithium atom has a radius of 152 picometers. What is its length in centimeters? A. 1.52 x 10-10 B. 1.52 x 1012 C. 1.52 x 108 D. 1.52 x 10-8 E. 1.52 x 10-12

D

An element with the following electron configuration is likely to form ____ with the charge of ____. 1s2 2s2 2p6 3s2 3p3 A. an anion, +3 B. a cation, +2 C. an anion, -2 D. an anion, -3 E. a cation, +3

D

Choose which central atom in the following molecules is most electronegative. A. H2S B. CH4 C. PH3 D. H2O E. NH3

D

For a hydrogen atom, calculate the wavelength of an emitted photon in the Lyman series that results from the transition n = 2.00 to n = 1.00. Rydberg constant is 1.097E+7 m-1. (h = 6.626E-34 J×s and c = 2.998E+8 m/s) A. 1.22E-16 nm B. 1.22E-7 nm C. -1.22E-7 nm D. 122 nm E. 8.23E+6 nm

D

How many moles of chloride are present in 4.87 grams of magnesium chloride? A. 0.137 B. 0.0512 C. 927 D. 0.102 E. 464

D

How many protons, neutrons and electrons are present in one ion of 31P3-? A. protons = 15, neutrons = 31 , electrons = 15 B. protons = 15, neutrons = 16, electrons = 12 C. protons = 31, neutrons = 15, electrons = 3 D. protons = 15, neutrons = 16, electrons = 18

D

How many protons, neutrons and electrons are there in a neutral atom of the isotope of copper named copper-65? A. 36, 29, 36 B. 29, 36, 36 C. 29, 65, 29 D. 29, 36, 29

D

Identify the ions present in KClO4. A. K+, Cl-, and O2- B. KCl2+ and O42- C. K2+ and ClO42- D. K+ and ClO4- E. KCl+, and O4-

D

Identify the ions present in Na2SO4. A. Na+ and SO4- B. Na+, S2-, and O2- C. Na+, S2-, and O2+ D. Na+ and SO42- E. Na+, S2+, and O2-

D

If 7.33 g NaNO3 is dissolved in enough water to make 390 mL of solution, what is the molarity of the sodium nitrate solution? A. 29.7 M B. 2.21E-4 M C. 8.62E-2 M D. 0.221 M E. 3.36E-2 M

D

If a gas effuses 1.21 times faster than Xe, what is its molar mass? A. 159 g/mol B. 192 g/mol C. 52.0 g/mol D. 89.7 g/mol E. 109 g/mol

D

Iron reacts with oxygen to produce iron(III) oxide. 4 Fe(s) + 3 O2(g) → 2 Fe2O3(s) If 3.16 moles of Fe react with excess O2, how many moles of Fe2O3 can be formed? A. 2.11 mol B. 3.16 mol C. 6.32 mol D. 1.58 mol E. 1.85 mol

D

One resonance structure for OCN- ion is drawn below. What is the formal charge on each atom? [Image unable to load - look up lewis structure of OCN- ion] A. O atom = 0, C atom = 0, and N atom = -1 B. O atom = -1, C atom = -1, and N atom = +1 C. O atom = +1, C atom = 0, and N atom = -2 D. O atom = -1, C atom = 0, and N atom = 0 E. O atom = 0, C atom = 0, and N atom = 0

D

Place the following ions in order from smallest to largest ionic radii: Se2-, Sr2+, Y3+, and Br-. A. Se2- < Br- < Sr2+ < Y3+ B. Se2- < Sr2+ < Y3+ < Br- C. Br- < Se2- < Y3+ < Sr2+ D. Y3+ < Sr2+ < Br- < Se2- E. Sr2+ < Y3+ < Se2- < Br-

D

Round 0.00764369 to 3 significant figures. A. 0.01 B. 0.0 C. 0.008 D. 0.00764 E. 0.0076

D

Rubidium has two naturally occurring isotopes. The average mass of Rb is 85.4678 u. If 72.15% of Rb is found as Rb-85 (84.9117 u), what is the mass of the other isotope? A. 85.68 u B. 86.02 u C. 83.47 u D. 86.91 u E. 0.56 u

D

Sodium azide decomposes rapidly to produce nitrogen gas. 2 NaN3(s) → 2 Na(s) + 3 N2(g) What mass of sodium azide will inflate a 63.9 L airbag for a car to a pressure of 1.64 atm at 23.1 °C? (R = 0.08206 L×atm/mol×K) A. 420 g B. 5.39E+3 g C. 2.40E+3 g D. 187 g E. 4.42E-2 g

D

The density of H2 gas in a rigid container is 0.212 g/L at a given temperature. What is the pressure of hydrogen in the flask if it is heated to 156 °C? (R = 0.08206 L×atm/mol×K) A. 35.2 atm B. 0.271 atm C. 336 atm D. 3.70 atm E. 1.34 atm

D

The density of ice at 0 °C is 0.917 g/mL. What is the volume of 160 g of ice? A. 1.74E+5 mL B. 0.174 mL C. 5.73E-3 mL D. 174 mL E. 147 mL

D

Use VSEPR Theory to predict the molecular geometry around the central atom in each of the following molecules. Which of the following molecular geometries are correct? 1. XeF4, square planar 2. ICl4-, tetrahedral 3. SF4, seesaw A. 1 and 2 B. 1, 2 and 3 C. 2 only D. 1 and 3 E. 3 only

D

Use VSEPR theory to predict the molecular geometry of BrO4-. A. See-saw B. Square pyramid C. Trigonal pyramid D. Tetrahedral E. Square planar

D

What is the formal charge for each atom in the structure below? [Image unable to load - look up lewis structure of SCO] A. S = +2, C = -1, O = -1 B. S = 0, C = 0, O = 0 C. S = 0, C = 0, O = -1 D. S = -1, C = 0, O = +1 E. S = +1, C = -1, O = 0

D

What is the hybridization of the sulfur atom in sulfur tetrafluoride, SF4? A. sp3d2 B. sp2 C. sp D. sp3d E. sp3

D

What is the pH of 3.36E-2 M HCl(aq)? A. 1.68 B. 1.27 C. -1.47 D. 1.47 E. 3.39

D

What type of orbital is designated n = 4, l= 2, ml = -2? A. None B. 4p C. 4s D. 4d E. 4f

D

When the following molecular equation is balanced using the smallest possible integer coefficients, the values of these coefficients are: __sodium fluoride (s) + __oxygen (g) --> __sodium oxide (s) + __fluorine (g) A. 2, 1, 1, 2 B. 2, 1, 1, 1 C. 2, 1, 2, 2 D. 4, 1, 2, 2 E. 4, 2, 1, 2

D

Which electron configuration corresponds to an element with chemistry similar to zirconium, Zr? 1. 1s2 2s2 2p6 3s2 3p6 4s2 4d2 2. 1s2 2s2 2p6 3s2 3p6 4s2 3d2 3. 1s2 2s2 2p6 3s2 3d2 A. 3 only B. l, 2 and 3 C. 1 only D. 2 only E. 1 and 2

D

Which of the electron configurations below correspond to an element with chemistry similar to selenium, Se? 1. 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p4 2. 1s2 2s2 2p6 3s2 3p4 3. 1s2 2s2 2p6 3s2 3p6 4s2 3d4 A. 1, 2 and 3 B. 2 only C. 3 only D. 1 and 2 E. 1 only

D

Which of the following are paramagnetic? 1. Li 2. Mg 3. N A. 3 only B. None C. 1 and 2 D. 1 and 3 E. 2 only

D

Which of the following are strong acids? 1. Hydrochloric acid 2. Sulfuric acid 3. Acetic acid 4. Nitric acid A. 1 and 3 B. all of these are strong acids C. 1 and 2 D. 1, 2 and 4 E. 2 only

D

Which of the following characteristics apply to NCl3? 1. polar bonds 2. nonpolar molecule 3. triangular-planar molecular shape 4. sp2 hybridized A. 1, 2, and 3 B. 1, 2, 3, and 4 C. 3 and 4 D. 1 only E. 1 and 2

D

Which of the following chemical equations refers to the electron affinity (EA) of I? A. I(s) +e? I-(s) B. I(g) +2e? I2-(g) C. I(g) -e? I+(g) D. I(g) +e? I-(g) E. I(s) +2e? I2?(s)

D

Which of the following compounds are named correctly? 1. NO2, nitrogen oxide 2. PCl5, phosphorous pentachloride 3. NH4I, ammonium monoiodide A. 2 and 3 B. 1 and 2 C. 1 only D. 2 only E. 1 and 3

D

Which of the following molecules are polar? 1. NF3 2. SF6 3. BrF5 A. 1 and 2 B. None C. 3 only D. 1 and 3 E. 1 only

D

The heat transferred in an endothermic reaction is 27 kJ and the internal energy increased by 34 kJ. Calculate the work involved in the process.

7 kJ

In the laboratory, a student determines the specific heat of a metal. He heats 19.1 grams of iron in 99.17 C and then drops it into an insulated cup containing 82.6 grams of water at 24.17 C. When thermal equilibrium is reached, he measures the final temperature to be 25.90 C. Assuming that all of the heat is transferred to the water, he calculates the specific heat of iron to be...

0.43 J/g C

FeO(s) + Hg(l) --> Fe(s) + HgO(s) Hrxn = ? 1) 2Fe(s) + O2(g) --> 2FeO(s) H = -544.0 kJ 2) 2Hg(l) + O2(g) --> 2HgO(s) H = -181.6 kJ Use Hess's Law to find the delta Hrxn of the reaction.

181.2 kJ

A compound is found to contain 74.76% by mass F and 25.24% by mass S, with a molecular weight of 254.14. What is the molecular formula for this compound? A. SF4 B. S2F6 C. S2F10 D. SF5 E. SF3

C

A 0.237 g sample of boron contains ____ B atoms. A. 3.94E-25 B. 2.19E-2 C. 1.32E+22 D. 3.64E-26 E. 1.43E+23

C

Atomic number is the________ in the nucleus of an atom. A. sum of the number of neutrons and protons B. number of protons minus the number of neutrons C. number of electrons D. sum of the number of electrons and neutrons E. number of protons

E

For which of the following molecules does the carbon atom have sp3 hybridization? A. HCN B. CO C. Cl2CO D. CS2 E. CH2Cl2

E

How many protons, neutrons, and electrons are in a silver atom with a mass number of 108? A. 47 protons, 47 neutrons, 61 electrons B. 61 protons, 47 neutrons, 47 electrons C. 47 protons, 108 neutrons, 47 electrons D. 61 protons, 108 neutrons, 61 electrons E. 47 protons, 61 neutrons, 47 electrons

E

How many resonance structures are needed to describe the bonding in ozone, O3? What is the O-O bond order? A. 1, 1 B. 2, 1 and 2 C. 3, 1.333 D. 2, 1.333 E. 2, 1.5

E

If an aqueous solution of ____ is added to a mixture of Cl - and SO42-, the sulfate ion will precipitate, but the chloride ion will remain in solution. A. Pb(ClO4)2 B. AlCl3 C. LiBr D. HNO3 E. Ca(NO3)2

E

Rank F, Cl, and Br in order of increasing first ionization energy. A. Br < F < Cl B. F < Cl < Br C. Cl < Br < F D. Cl < F < Br E. Br < Cl < F

E

The lid is tightly sealed on a rigid flask containing 1.50 L Ar at 28.0 °C and 0.775 atm. If the flask is heated to 111 °C, what is the pressure in the flask? A. 0.608 atm B. 0.494 atm C. 3.07 atm D. 1.98 atm E. 0.989 atm

E

What are the oxidation numbers of nitrogen in each of the following compounds NH3, N2H4, and NO3-, respectively? A. +3, -2 , -3 B. +5, +3, -2 C. -3, +4, +2 D. +4, -2, -1 E. -3, -2, +5

E

What is the correct answer to the following expression: (204.49 - 144.40) ÷ 5.900? A. 180.02 B. 10 C. 10.2 D. 1E+1 E. 10.18

E

What is the molar mass of sodium sulfate? A. 110.0 g/mol B. 119.1 g/mol C. 78.05 g/mol D. 55.06 g/mol E. 142.0 g/mol

E

What volume of 3.05 M HNO3(aq) must be diluted to make 4.10 L of 0.148 M HNO3(aq)? A. 84.5 L B. 0.607 L C. 5.03 L D. 2.05 L E. 0.199 L

E

Which element is most likely to form a 2- ion? A. Mg B. Br C. K D. P E. S

E

Which has the longest O-O bond? Which has the strongest? 1. H2O2 2. O2 A. 2, 1 B. 2, 2 C. 1, 1 D. They have the same bond length and bond strength E. 1, 2

E

Which of the following chemical equations refers to the third ionization of Al? A. Al(s) +2e? Al2?(s) B. Al(s) +e? Al+(s) C. Al+(g) -2e? Al3+(g) D. Al(g) -2e? Al2+(g) E. Al2+(g) -e? Al3+(g)

E

Which of the following compounds are named correctly? 1. CrCl3, chromium(II) chloride 2. PCl3, phosphorous chloride 3. NF3, nitrogen trifluoride A. 2 and 3 B. 2 only C. 1 and 3 D. None E. 3 only

E

Which one of the following statements is correct? A. A heterogeneous mixture is composed of two or more substances in the same phase. B. A heterogeneous mixture is also known as a solution. C. A pure substance may be separated by filtration or distillation into two or more components. D. The combination of a liquid and a solid always results in a heterogeneous mixture. E. The composition is uniform throughout a homogeneous mixture.

E

Which one of the following substances is classified as an element? A. NO B. CO C. C6H12O6 D. KCl E. I2

E