Chem, Topic 6

In the reaction 5H₂O₂ + 2MnO₄⁻ + 6H⁺ → 2Mn₂⁺ + 8H₂O + 5O₂, what is the oxidizing agent? Select one: a. H2O2 b. MnO4⁻ c. H⁺ d. Mn2⁺ e. O₂

b. MnO4⁻

A possible set of quantum numbers for the last electron added to complete an atom of germanium in its ground state is n l ml ms A 4 0 0 +1/2 B 3 0 +1 -1/2 C 4 1 -1 +1/2 D 3 1 +1 -1/2 E 4 2 +2 -1/2 Select one: a. A b. B c. C d. D e. E

c. C

What wavelength, in nm, can strike a metal surface and eject an electron at 1.89 × 10-19 J if the binding energy of the metal is 289 kJ/mol? Select one: a. 1.89 × 10-19 nm b. 2.75 nm c. 189 nm d. 290 nm e. 297 nm

e. 297 nm

Line spectra from all regions of the electromagnetic spectrum, including the Paschen series of infrared lines for hydrogen, are used by astronomers to identify elements present in the atmospheres of stars. Calculate the wavelength of the photon emitted when the hydrogen atom undergoes a transition from n = 5 to n = 3. (R = 1.096776 × 107 m-1) Select one: a. 205.1 nm b. 384.6 nm c. 683.8 nm d. 1282 nm e. > 1500 nm

d. 1282 nm

The heat of solution of ammonium chloride is 15.2 kJ/mol. If a 6.134-g sample of NH4Cl is added to 65.0 mL of water in a calorimeter at 24.5°C, what is the final temperature of the solution? The specific heat of water is 4.18 J/g·°C and the heat capacity of the calorimeter is 365 J/°C. Select one: a. 27.1°C b. 18.6°C c. 19.7°C d. 21.8°C e. 30.4°C

d. 21.8°C

The highly exothermic thermite reaction, in which aluminum reduces iron(III) oxide to elemental iron, has been used by railroad repair crews to weld rails together. 2Al(s) + Fe₂O₃(s) → 2Fe(s) + Al₂O₃(s) ΔH°rxn= -847.6 kJ/mol What mass of iron is formed if 725 kJ of heat are released? Select one: a. 23.9 g b. 47.8 g c. 65.3 g d. 95.5 g e. 112 g

d. 95.5 g

Which element is reduced in the following reaction? Cu + 2H₂SO₄ → CuSO₄ + SO₂ + 2H₂O Select one: a. Cu b. H c. S d. O e. H2O

c. S

The bond enthalpy of the Br-Cl bond is equal to ΔH°(subscript rxn) for the following reaction. BrCl(g) → Br(g) + Cl(g) Using the following data, what is the bond enthalpy of the Br-Cl bond? Br2(l) → Br₂(g) ΔH°rxn = 30.91 kJ/mol Br₂(g) → 2Br(g) ΔH°rxn = 192.9 kJ/mol Cl₂(g) → 2Cl(g) ΔH°rxn = 243.4 kJ/mol Br₂(l) + Cl₂(g) → 2BrCl(g) ΔH°rxn = 29.2 kJ/mol Select one: a. 219.0 kJ/mol b. 203.5 kJ/mol c. 14.6 kJ/mol d. 438.0 kJ/mol e. 407.0 kJ/mol

a. 219.0 kJ/mol

List the following types of radiation from lowest frequency to highest frequency: microwave, X ray, ultraviolet, visible, and infrared Select one: a. microwave < infrared < visible < ultraviolet < X ray b. X ray < ultraviolet < visible < infrared < microwave c. visible < ultraviolet < microwave < X ray < infrared d. infrared < X ray < microwave < ultraviolet < visible e. infrared < visible < microwave < ultraviolet < X ray

a. microwave < infrared < visible < ultraviolet < X ray

The energy of an electron in the hydrogen atom is determined by Select one: a. the principal quantum number (n) only. b. the angular momentum quantum number (l) only. c. the principal and angular momentum quantum numbers (n & l). d. the principal and magnetic quantum numbers (n & ml). e. the principal, angular momentum, and magnetic quantum numbers.

a. the principal quantum number (n) only.

An exothermic reaction causes the surroundings to Select one: a. warm up. b. become acidic. c. expand. d. decrease its temperature. e. release CO₂.

a. warm up.

Which of the following is a strong acid? Select one: a. H₃PO₄ b. HNO₃ c. HF d. CH₃COOH e. H₂O

b. HNO₃

The electronic structure 1s²2s²2p⁶3s²3p⁶4s²3d⁸ refers to the ground state of Select one: a. Kr. b. Ni. c. Fe. d. Pd. e. None of these choices is correct.

b. Ni.

Given that CaO(s) + H₂O(l) → Ca(OH)₂ₙ(s), ΔH°(subscript rxn) = -64.8 kJ/mol, how many grams of CaO must react in order to liberate 525 kJ of heat? Select one: a. 6.92 g b. 56.1 g c. 454 g d. 606 g e. 3.40 × 10⁴ g

c. 454 g

Which salt is produced by the neutralization of hydrobromic acid with magnesium hydroxide? Select one: a. MgBr b. Mg₂Br₃ c. MgBr₂ d. Mg₃Br₂ e. Mg₂Br

c. MgBr₂

In which process is ΔH = ΔU? Select one: a. Two moles of ammonia gas are cooled from 325°C to 300°C at a constant pressure of 1.2 atm. b. One gram of water is vaporized at 100°C and 1 atm. c. Two moles of hydrogen iodide gas react to form hydrogen gas and iodine gas in a 40-L container. d. Solid calcium carbonate is heated to form solid calcium oxide and carbon dioxide gas in a container with variable volume. e. One mole of solid carbon dioxide sublimes to the gas phase.

c. Two moles of hydrogen iodide gas react to form hydrogen gas and iodine gas in a 40-L container.

The electron configuration of a ground-state vanadium atom is Select one: a. [Ar]4s²4d³. b. [Ar]4s²4p³. c. [Ar]4s²3d³. d. [Ar]3d⁵. e. [Ar]4s²3d⁷.

c. [Ar]4s²3d³.

If one s orbital were combined with one p orbital (dumbbell shaped), which would best describe the resulting shape? Select one: a. spherical b. mostly spherical, slightly dumbbell c. an equal ratio of spherical and dumbbell d. slightly spherical, mostly dumbbell e. mostly dumbbell

c. an equal ratio of spherical and dumbbell

Based on the solubility rules, which one of these compounds is insoluble in water? Select one: a. NaCl b. MgBr₂ c. FeCl₂ d. AgBr e. ZnCl₂

d. AgBr

For the reaction depicted below, if Z represents Zn, which metal could A represent? *Image* Select one: a. Fe b. Co c. Pb d. Ca e. Cu

d. Ca

Which accurately characterizes all nonelectrolyte solutions? Select one: a. Nonelectrolyte solutions contain molecules. b. Nonelectrolyte solutions conduct electricity. c. Nonelectrolyte solutions react with other solutions. d. Nonelectrolyte solutions do not conduct electricity. e. Nonelectrolyte solutions conduct heat.

d. Nonelectrolyte solutions do not conduct electricity.

Which of these is not a state function? Select one: a. volume b. temperature c. pressure d. heat e. energy

d. heat

Which of these chemical equations does not describe a redox reaction? Select one: a. 2KBr(aq) + Cl₂(g) → 2KCl(aq) + Br₂(l) b. 2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g) c. 3NO₂(g) + H₂O(l) → 2HNO₃(aq) + NO(g) d. 2KNO₃(s) → 2KNO₂(s) + O₂(g) e. 2LiOH(aq) + H₂SO₄(aq) → Li₂SO₄(aq) + 2H₂O(l)

e. 2LiOH(aq) + H₂SO₄(aq) → Li₂SO₄(aq) + 2H₂O(l)

What is the change in temperature if a 25.0-g block of aluminum absorbs 10.0 kJ of heat? The specific heat of aluminum is 0.900 J/g·°C. Select one: a. 0.44°C b. 22.5°C c. 225°C d. 360°C e. 444°C

e. 444°C

Which of these compounds is a nonelectrolyte? Select one: a. NaF b. HNO₃ c. CH₃COOH (acetic acid) d. NaOH e. C₆H₁₂O₆ (glucose)

e. C₆H₁₂O₆ (glucose)