Chem Exam 2

Beta emission leads to A. increase in nuclear charge B. increase in mass number C. decrease in nuclear charge D. decrease in mass number E. none of above is correct

A. increase in nuclear charge

Arrange in order of increasing atomic radius. A. F < Na < Mg B. F < Mg < Na C. Na < Mg < F D. Mg < Na < F E. All three have the same radius.

B. F < Mg < Na

The ground state electron configuration for Sn4+ is A. [Kr] B. [Kr] 4d10 C. [Kr] 4d10 5s2 D. [Kr] 4d10 5s2 5p6 E. [Xe]

B. [Kr] 4d10

How much energy is evolved in the transition from the n = 2 to the n = 1 level for 0.5 mol hydrogen? A. 0.763 kJ B. -0.763 kJ C. 492 kJ D. -492 kJ

C. 492 kJ

Which one of the following is not a redox reaction? A. 2H2O2(aq) --> 2H2O(l) + O2(g) B. N2(g) + 3H2(g) --> 2NH3(g) C. BaCl2(aq) + K2CrO4(aq) --> BaCrO4(aq) + 2KCl(aq) D. 2Al(s) + Fe2O3(s) --> Al2O3(s) + 2Fe(s) E.2H2O(g) --> 2H2(g) + O2(g)

C. BaCl2(aq) + K2CrO4(aq) --> BaCrO4(aq) + 2KCl(aq)

The electron configuration 1s2 2s2 2p6 3s2 3p6 could correspond to which of the following? A. O2- B. N3- C. K+ D. all of the above

C. K+

Which two elements are most similar in chemical properties? A. Si and P B. P and S C. N and P D. P and Bi

C. N and P

What is the term used to indicate zero probability for finding a particle at a point in space? A. orbital B. cusp C. node D. quantum level

C. node

Which of the following elements is paramagnetic? A. Kr B. Zn C. Sr D. V E. Ar

D. V

The H atom transition n = 5 to n = 1 is more energetic than A. n=3 to n=1 B. n=4 to n=3 C. n=5 to n=4 D. all of these

D. all of these

If a radioisotope has a half-life of 2.0 hours, how long would it take for 93.7% of a sample to decompose? A. 16 hours B. 14 hours C. 12 hours D. 10 hours E. 8 hours

E. 8 hours

A system releases 1275 J of heat, while the surroundings perform 855 J of work on the system. Calculate delta E in J. A. -2130 J B. -420 J C. 420 J D. 2130 J e. -1275 J

B. -420 J

A sample of 95 g of a metal at 75°C is placed in 50. g of water at 18°C. If the final temperature of the water is 23°C, find the specific heat of the metal. (Specific heat of water is 4.184 J/g°C.) A. 23 J/g°C B. 0.21 J/g°C C. 0.76 J/g°C D. 3.6 J/g°C

B. 0.21 J/g°C

Which one of the following atoms has no unpaired electrons in its ground-state? A. N B. Mg C. Cl D. Na E. B

B. Mg

Which of the following forms of electromagnetic radiation has the shortest wavelength? A. ultraviolet B. x-ray C. microwave D. infrared

B. x-ray

Select the element with the least metallic character. A. Sn B. Sr C. Tl D. Ge E. Ga

D. Ge

Which one of the following species has the highest first ionization energy? A. Be B. B C. Ne D. He E. N

D. He

Select the diamagnetic ion. A. Cu2+ B. Ni2+ C. Cr3+ D. Sc3+ E. Cr2+

D. Sc3+

54. The element below with the smallest atomic radius is A. Rb B. Ca C. Al D. C E. O

E. O

Which one of the following statements about orbital energies is incorrect? A. In the hydrogen atom, the energy of an orbital depends only on the value of the quantum number n. B. In many-electron atoms the energy of an orbital depends on both n and l. C. Inner electrons shield outer electrons more effectively than do electrons in the same orbital. D. The splitting of sublevels in many-electron atoms is explained in terms of the penetration effect. E. The energy of a given orbital increase as the nuclear charge Z increases.

E. The energy of a given orbital increase as the nuclear charge Z increases.

Which of the following orbitals cannot exist? A. 2s B. 2p C. 4d D. 4f E. all exist

E. all exist

Given the following data: 2O3(g) --> 3O2(g) delta H= -427 O2(g) --> 2O(g) delta H= +495 NO(g) + O3(g) --> NO2(g) + O2(g) delta H= 0-199 Calculate delta H for the reaction NO(g) + O(g) ---> NO2(g) Is the reaction endothermic or exothermic?

110. -233kJ

The electronic structure 1s2 2s2 2p6 3s2 3p6 4s2 3d8 refers to the ground state of A. Kr B. Ni C. Fe D. Pd E. none of these choices is correct

B. Ni

In the reaction 232/90 Th--> 4/2He + X the resulting element X is: A. Ac B. Ra C. Th D. U

B. Ra

Which of the following statements is true? A. Cations are always larger than the neutral atom from which they are derived. B. Anions are always smaller than the neutral atom from which they are derived. C. Cations are always smaller than the neutral atom from which they are derived. D. None of the above.

C. Cations are always smaller than the neutral atom from which they are derived.

The most stable nuclides, in general, have ___ numbers of neutrons and ___ numbers of protons. A. odd, even B. odd, odd C. even, even D.even, odd E. odd, equal

C. even, even

Use the following data to calculate the standard heat (enthalpy) of the formation delta H°f, of manganese(IV) oxide, MnO2 (s). 2MnO2(s) --> 2MnO(s) + O2(g) delta H = 264 kJ MnO2(s) + Mn(s) --> 2MnO(s) delta H = -240 kJ A. -504 kJ B. -372 kJ C. -24 kJ D. 24 kJ E. 504 kJ

A. -504 kJ

An important step in the synthesis of nitric acid is the conversion of ammonia to nitric oxide. delta H°f [NH3(g)] = -49.5 kJ/mol delta H°f [NO(g0]= 90.3 kJ/mol delta H°f [H2O(g)] = -241.8 kJ/mol 4NH3(g)+ 5O2(g) --> 4NO(g) + 6H2O(g). Calculate delta H°rxn for this reaction. A. -906.0 kJ B. -197.4 kJ C. -105.6 kJ D. 197.4 kJ E. 906.0 kJ

A. -906.0 kJ

How many unpaired electrons are in a ground state beryllium atom?A. 0 B. 1 C. 2 D. 4

A. 0

The respective masses in amu of the proton, the neutron, and the nickel-60 nucleus are1.00728, 1.00867, and 59.9308. What is the mass defect of the nickel-60 nuclide in amu? A. 0.5505 amu B. 0.5449 amu C. 0.6060 amu D. 0.6111 amu

A. 0.5505 amu

What is the electron configuration of Ne? A. 1s2 2s2 2p6 B. [He]2p6 C. 1s2 2p6 D. 2s2 2p6 E. 2p6

A. 1s2 2s2 2p6

The standard molar enthalpy of formation for Na2CO3(s) is -1131 kJ mol-1. Which equation below represents this reaction? A. 2Na(s) + C(graphite) + 3/2 O2(g)-->Na2CO3(s) B. Na2O(s) + CO2(g) --> Na2CO3(s) C. 2Na(s) + CO2(g) + 1/2 O2(g) --> Na2CO3(s) D. Na2O(s) + C(graphite) + O2(g) --> Na2CO3(s)

A. 2Na(s) + C(graphite) + 3/2 O2(g)-->Na2CO3(s)

The mass defect of an isotope is 0.410 amu/atom. Calculate the binding energy in J/mol of atoms. A. 3.69 x 10^13 J/mol B. 1.23 x 10^20 J/mol C. 3.69 x 10^3 J/mol D. 1.23 x 10^3 J/mol E. 1.23 x 10^23 J/mol

A. 3.69 x 10^13 J/mol

What is the wavelength of a photon with energy of 5.25 x 10-19 J? A. 3.79 x 10-7 m B. 2.64 x 106 m C. 2.38 x 1023 m D. 4.21 x 10-24 m

A. 3.79 x 10-7 m

Which of the following experiences the greatest effective nuclear charge in a many-electron atom? A. 3d B. 4p C. 4d D. 4f E. 5s

A. 3d

Identify the orbital which could be designated by the quantum number n = 3 and l =2. A. 3dz2 B. 3s C. 3pz D. 3px

A. 3dz2

What is the velocity of the electron with a de Broglie wavelength of 1.00 m? (me= 9.11 x 10^-31 kg) A. 7.28 x 10^-4 m/s B. 8.44 x 10^-2 m/s C. 3.00 x 10^8 m/s D. 9.00 x 10^16 m/s E. 5.20 x 10^18 m/s

A. 7.28 x 10^-4 m/s

An electron of a hydrogen atom is in a 5g orbital. What is the energy required to excite it to n = ∞? A. 8.72 x 10^-20 J B. 1.74 x 10^-20 J C. 2.18 x 10^-18 J D. 2.09 x 10^-18 J E. 4.18 x 10^-19 J

A. 8.72 x 10^-20 J

Which statement is incorrect? A. The standard state of a pure substance is the most stable form of the substance at 1atm and 273 K. B. Enthalpy is a state function. C. Energy can neither be created nor destroyed. D. A process that absorbs heat from the surroundings is called endothermic E. The law of conservation of energy is another statement of the first law of thermodynamics.

A. The standard state of a pure substance is the most stable form of the substance at 1atm and 273 K.

An isotope with Z > 83, which lies close to the band of stability, will generally decay through A. alpha decay B. beta decay C. y decay D. positron emission. E. electron capture

A. alpha decay

Infrared radiation from the sun has a wavelength of 6200 nm. Calculate the energy of one photon of that radiation. A. between 10-20 and 10-19 J B. 4.l × l0-30 J C. 3.2 × 10-29 J D. 3.2 × 10-26 J

A. between 10-20 and 10-19 J

Which one of the following elements has the highest first ionization energy? A. carbon B. silicon C. germanium D. tin

A. carbon

Which group is represented by the valence electron configuration ns2 np4? A. chalcogens B. noble gases C. halogens D. alkali metals E. alkali earth metals

A. chalcogens

Atomic orbitals developed using quantum mechanics A. describe regions of space in which one is most likely to find an electron. B. describe exact paths for electron motion. C. give a description of the atomic structure which is essentially the same as the Bohr model. D. allow scientists to calculate an exact volume for the hydrogen atom. E. are in conflict with the Heisenberg Uncertainty Principle.

A. describe regions of space in which one is most likely to find an electron.

Which of the following is a correct set of quantum numbers for an electron in a 5f orbital? A. n = 5, l = 3, ml = +1 B. n = 5, l = 2, ml = +3 C. n = 4, l = 3, ml = 0 D. n = 4, l = 2, ml = +1 E. n = 5, l = 4, ml = 3

A. n = 5, l = 3, ml = +1

Which of the following is a valid set of quantum numbers (n, l, ml, ms)? A. (2, 1, 2, 1/2) B. (4, 2, 0, 1/2) C. (3, 3, 1, -1/2) D. (3, 1, 3, 1/2) E. (1, 1, 1, 1/2)

B. (4, 2, 0, 1/2)

Which of the following configuration represents an excited state configuration? A. 1s2 2s2 B. 1s2 2p6 C. 1s2 2s2 2p4 D. 1s2 2s2 2p1

B. 1s2 2p6

Calculate the molar heat capacity of Al(s) if its specific heat is 0.900 J g-1 K-1. A. 0.900 J mol^-l K^-1 B. 24.3 J mol^-l K^-1 C. 27.0 J mol^-l K^-1 D. 30.0 J mol^-l K^-1

B. 24.3 J mol^-l K^-1

Which of the following is a strong electrolyte? A. NH3 B. Ca(OH)2 C. Al(OH)3 D. HF E. CH3OH

B. Ca(OH)2

Which neutral element below has a valence shell electron configuration 4s2 4p4 ? A. S B. Se' C. Sb D. As E. Br

B. Se

Which of the following is a true statement of Hess's Law? A. The energy of the universe is a constant. B. The total enthalpy change in a chemical reaction is independent of the number and nature of intermediate steps that may be involved in that reaction. C. Reversing the direction of a reaction changes the sign of the enthalpy change for the reaction. D. All elements in their standard states have zero heats of formation. E. The enthalpy change for any process is the heat absorbed or released.

B. The total enthalpy change in a chemical reaction is independent of the number and nature of intermediate steps that may be involved in that reaction.

Alpha decay is due to A. fusion of an electron and a proton B. ejection of a helium nucleus with +2 charge C. ejection of a high-energy electron. D. capture of an electron. E. ejection of a positron.

B. ejection of a helium nucleus with +2 charge

In the following transformation, S(s) --> S(g) --> S(l) the overall process S(s) ---> S(l) is A. exothermic. B. endothermic. C. isothermal. D. isochoric.

B. endothermic.

The Photoelectric effect demonstrated that A. electron energy is proportional to velocity. B. light energy is proportional to frequency. C. energy of a photon is proportional to light intensity. D. both A and B are true. E. both B and C are true.

B. light energy is proportional to frequency.

An electron in the n = 6 level emits a photon with a wavelength of 410.2 nm. To what energy level does the electron move? A. n = 1 B. n = 2 C. n = 3 D. n = 4 E. n = 5

B. n = 2

A system that does no work but transfers heat to the surroundings has A. q<0, delta E > 0 B. q<0, delta E < 0 C. q>0, delta E > 0 D. q>0, delta E < 0 E. q<0. delta E=0

B. q<0, delta E < 0

The isotope 42/21 Sc is unstable. This is predictable because A. the number of neutrons is too large in relation to the number of protons. B. the number of neutrons is too small in relation to the number of protons. C. the atomic number is too large. D. the mass number is too large. E. Sc isotopes are all unstable.

B. the number of neutrons is too small in relation to the number of protons

Which set of quantum numbers (n, l, ml, ms) is valid? A. (4, 4, 0, 0) B. (4, 4, 1, 1/2) C. (3, 2, -1, 1/2) D. (1, 0, 0, 0) E. (3, 2, 3, 1/2)

C. (3, 2, -1, 1/2)

A 7.5 x 10^4 g block of an unknown metal absorbs 9.2 x 10^5 J of energy to raise its temperature by 25 K. Calculate the specific heat of the metal block. A. 24 J/g K B. 2.0 J/g K C. 0.49 J/g K D. 0.041 J/g K

C. 0.49 J/g K

The neutron-to-proton ratio puts a nucleus above the belt of stability (n vs. p). What type of radioactive decay should be expected? A.1/1 H B. 1/0 n C. 0/-1 e D. 0/+1 e E. 4/2 He

C. 0/-1 e

How many electrons are required to completely fill orbitals with n = 5 and l = 3? A. 2 B. 9 C. 14 D. 25 E. 50

C. 14

The half-life of Sr-83 is 32.4 hours. How much of a Sr-83 sample will be left after 75.0hours? A. 2.48% B. 18.4% C. 20.1% D. 23.1% E. 43.2%

C. 20.1%

Vinegar is a solution of acetic acid, CH3COOH, dissolved in water. A 5.54-g sample of vinegar was neutralized by 30.10 mL of 0.100 M NaOH. What is the percent by weight of acetic acid in the vinegar? A. 0.184% B. 1.63% C. 3.26% D. 5.43% E. 9.23%

C. 3.26%

Given the following information: CaO(s) + H2O(l) ĺ Ca(OH)2(s) (delta)H = -64.8 kJ How many grams of CaO must react in order to liberate 525 kJ of heat? A. 6.92 g B. 56.1 g C. 454 g D. 606 g E. 3.40 x 10^4 g

C. 454 g

What is the resulting temperature in °C when 35 g of water at 75°C is mixed with 15 g of water at 15°C? (Specific heat of H2O = 4.184 J/g°C) A. 33 B. 48 C. 57 D. 120

C. 57

Heisenberg Principle deals with A. the relationship between energy and frequency of a photon. B. the wavelength of transitions in the hydrogen atom. C. determining the position and momentum of a particle simultaneously. D. determining allowed quantum numbers.

C. determining the position and momentum of a particle simultaneously.

15. Arrange in order of increasing frequency: A. red light < violet light < infrared light B. violet light < red light < infrared light C. infrared light < red light < violet light D. infrared light < violet light < red light

C. infrared light < red light < violet light

Nuclear fission A.is the process by which the light nuclei combine to form a heavier nucleus with the release of energy. B. occurs when a nucleus's atomic number is smaller than 84. C. is the process by which a heavier nucleus splits into lighter nuclei with the release of energy. S. releases energy because the total mass of reactants is more than that of the products. E.All of the above are correct.

C. is the process by which a heavier nucleus splits into lighter nuclei with the release of energy.

The main reason why atomic radius decreases with increasing atomic number along a period is because of A. number of neutrons. B. number of principal quantum levels. C. nuclear attraction for orbital electrons. D. interelectronic repulsion.

C. nuclear attraction for orbital electrons.

Select the classification for the following reaction. Fe(s) + 2Fe3+(aq) ---> 3Fe2+(aq) A. precipitation B. acid-base C. redox D. decomposition E. none of these choices is correct

C. redox

Calcium hydroxide, which reacts with carbon dioxide to form calcium carbonate, was used by the ancient Romans as mortar in stone structures. The reaction for this process is Ca(OH)2(s) + CO2(g) ĺ CaCO3(s) + H2O(g) (delta)H = -69.1 kJ What is the enthalpy change if 380. g of calcium carbonate is formed? A. -18 kJ B. -69.1 kJ C. +69.1 kJ D. -263 kJ E. +263 kJ

D. -263 kJ

The Bohr theory of the hydrogen atom predicts the energy difference (in J) between the n = 3 and the n = 5 state to be A. 8.72 × 10^-20 J B. 1.36 × 10^-19 J C. 2.42 × 10^-19 J D. 1.55 × 10^-19 J E. 1.09 × 10^-18 J

D. 1.55 × 10^-19 J

The specific heat of lead is 0.13 J/g°C. How many joules of heat would be required to raise the temperature of 0.0724 mol of lead from 22°C to 37°C? A. 2.0 J B. -.13 J C. 5.8 x 10^-4 J D. 29 J

D. 29 J

If the de Broglie wavelength of an electron is 2.00 x 10^-6 m, what is the velocity of this electron?(me= 9.11 x 10^-31 kg) A. .260 m/s B. 1022 m/s C. 6.77 x 10^4 m/s D. 364 m/s E. 3.31 x 10^-28 m/s

D. 364 m/s

Cu+(g) + I−(g) → CuI(g) ∆H° = -446 kJ If the ionization energy of Cu(g) is 745 kJ mol-1 and the electron affinity of I(g) is -295 kJ mol-1, then the value of ∆H° for the formation of one mole of CuI(g) ion-pairs from Cu(g) and I(g) is A. -446 kJ B. 450 kJ C. 594 kJ D. 4 kJ E. -896 kJ

D. 4 kJ

The shorthand notation for an orbital with quantum numbers n = 4, l = 3 is A. 4p B. 4d C. 3f D. 4f E. 1s

D. 4f

Select the correct set of quantum numbers (n, l, ml, ms) for the highest energy electron in the ground state of tin, Sn. A. 5, 2, -1, ½ B. 5, 2, 0, ½ C. 5, 1, 2, ½ D. 5, 1, 0, ½ E. 5, 2, 1, ½

D. 5, 1, 0, ½

If the wavelength of yellow light is 570 nm, what is its frequency? A. 171 Hz B. 7.60 x 10^3 Hz C. 1.16 x 10^-27 Hz D. 5.26 x 10^14 Hz E. 7.60 x 10^17 Hz

D. 5.26 x 10^14 Hz

The half life of 245/98 Cf is 44 minutes. If a sample contains 25.6 g of this matter, how much remains after about 1.5 hours? A. 1.6 g B. 3.2 g C. 4.3 g D. 6.2 g E. 8.5 g

D. 6.2 g

Which of the following is isoelectronic with Sr2+? A. Y3+ B. Rb C. Br − D. A and C E. A, B, and C

D. A and C

Which one of the following statements about atomic structure and quantum numbers is incorrect? A. In a given atom, the maximum number of electrons having principal quantum number n = 3,is 18 B. The number of orbitals in a given f subshell is 7. C. For n = 4, the largest possible value of l is 3. D. For n = 4, the largest possible value of ml is 2. E. The following set of quantum numbers for a single orbital is not allowed: n = 3, l = 1, ml = -2.

D. For n = 4, the largest possible value of ml is 2.

A set of degenerate orbitals must be singly occupied with electrons of the same spin before electrons can pair up A. Is a statement of Pauli exclusion principle B. Is a statement of aufbau principle C. Is a description of shielding effect D. Is a statement of Hund's rule E. Is a description of photoelectric effect

D. Is a statement of Hund's rule

Which of the following has the largest radius? A. Al3+ B. Na+ C. O2- D. N3-

D. N3-

The Pauli exclusion principle states A. The electron is not allowed to move in circular orbits about the nucleus. B. The energy of the universe is constant. C. All the quantum numbers must be equal. D. No two electrons in an atom can have the same set of four quantum numbers. E. Electrons are excluded from the nucleus

D. No two electrons in an atom can have the same set of four quantum numbers.

Which one of the following equations correctly represents the process involved in the electron affinity of X? A. X(g) → X+ (g) + e− B. X+ (g) → X+ (aq) C. X+ (g) + e− → X(g) D. X(g) + e− → X− (g) E. X+ (g) + Y− (g) → XY(s)

D. X(g) + e− → X− (g)

In wave (quantum) mechanical theory, A. particles are described from a probabilistic point of view. B. electrons do not travel in discrete orbits or trajectories. C. quantum numbers arise as a natural consequence of the theory. D. all of the above are true.

D. all of the above are true.

Which quantum number defines the shape of an orbital? A. spin B. magnetic C. principal D. azimuthal or orbital angular momentum

D. azimuthal or orbital angular momentum

Which d orbital has lobes aligned along a single axis? A. dx2 - y2 B. dxy C. dyz D. dz

D. dz

The radioisotope 82/38 Sr will decay through A. alpha decay B. beta decay C. y decay D. electron capture. E. spontaneous fission.

D. electron capture.

The energy of light A. is proportional to frequency. B. is proportional to wavelength. C. is inversely proportional to wavelength. D. follows both A and C above.

D. follows both A and C above.

Which one of the following electron transitions in a hydrogen atom results in the greatest release of energy from the atom? A. n=3 to n=1 B. n=1 to n=2 C. n=2 to n=1 D. n=4 to n=1 E. n=6 to n=5

D. n=4 to n=1

Automobile batteries use 3.0 M H2SO4 as an electrolyte. How much 1.20 M NaOH will be needed to neutralize 225 mL of battery acid? H2SO4(aq) + 2NaOH(aq) --> 2H2O(l) + Na2SO4(aq) A. 0.045 L B. 0.28 L C. 0.56 L D. 0.90 L E. 1.1 L

E. 1.1 L

Palladium-107 undergoes beta decay (T1/2 = 6.5 × 105 yr) to form silver-107. How long will ittake for 0.150 mol of silver-107 to form from 1.25 mol of palladium-107? A.2.0 × 10^7 y B. 1.4 × 10^7 y C. 1.2 × 10^6 y D. 8.3 × 10^5 y E. 1.2 × 10^5 y

E. 1.2 × 10^5 y

If the half-life of a radioactive element is 3.0 years, how much radioactivity of a sample of this element will remain after 12.0 years? A. 4 times of the original B. ½ of the original C. ¼ of the original D. 1/8 of the original E. 1/16 of the original

E. 1/16 of the original

Galena is the ore from which elemental lead is extracted. In the first step of the extraction process, galena is heated in air to form lead(II) oxide. 2PbS(s) + 3O2(g) ---> 2PbO(s) + 2SO2(g) delta H = -827.4 kJ What mass of galena is converted to lead oxide if 975 kJ of heat are liberated A. 203 g B. 282 g C. 406 g D. 478 g E. 564 g

E. 564 g

Which one of the following equations correctly represents the process relating to the ionization energy of X? A. X(s) → X+(g) + e− B. X2(g) → X+ (g) + X− (g) C. X(g) + e− → X− (g) D. X− (g) → X(g) + e− E. X(g) → X+ (g) + e−

E. X(g) → X+ (g) + e−