Ch6 Ch7 Ch8 Practice Q Key F18 PDF

Preview

Summary

Download Ch6 Ch7 Ch8 Practice Q Key F18 PDF

Description

CHAPTER 6, 7, AND 8 PRACTICE QUESTIONS KEY 1.

Green light can have a wavelength of 512 nm. The energy of a photon of this light is a) 1.02 x 10–31 J b) 5.12 x 10–7 J c) 3.88 x 10–19 J d) 5.86 x 1014 J e) 2.58 x 1018 J

2.

Which of the following statements is (are) true? I. An excited atom can return to its ground state by absorbing electromagnetic radiation II. The energy of an atom is increased when electromagnetic radiation is emitted from it. III. The energy of electromagnetic radiation increases as its frequency increases. IV. An electron in the n = 4 state in the hydrogen atom can go to the n = 2 state by emitting electromagnetic radiation at the appropriate frequency. V. The frequency and wavelength of electromagnetic radiation are inversely proportional to each other. a) b) c) d) e)

3.

II, III, IV III, IV, V I, II, III III, V I, II, IV Which of the following forms of electromagnetic radiation has the longest wavelength? a. microwaves b. ultraviolet c. infrared d. visible light e. radio-waves

4.

When a hydrogen electron makes a transition from n = 3 to n = 2, which of the following statements is true?

I. Energy is emitted. II. Energy is absorbed. III. The electron gains energy. IV. The electron loses energy. V. The electron cannot make this transition.

a) b) c) d) e)

I, IV I, III II, III II, IV V

5.

In Bohr's atomic theory, when an electron moves from one energy level to another energy level closer to the nucleus: a) Energy is emitted. b) Energy is absorbed. c) No change in energy occurs. d) Light is emitted. e) More than one of these might occur

6.

Which of the following best describes an orbital? a) a space in an atom where an electron is most likely to be found b) space where electrons are unlikely to be found in an atom c) space which may contain electrons, protons, and/or neutrons d) small, walled spheres that contain electrons e) a single space within an atom that contains all electrons of that atom

7.

Which of the following is not determined by the principal quantum number, n, of the electron in a hydrogen atom? a) The energy of the electron. b) the minimum wavelength of the light needed to remove the electron from the atom. c) The size of the corresponding atomic orbital(s). d) The shape of the corresponding atomic orbital(s). e) All of the above are determined by n.

8.

Which of the following is an incorrect designation for an atomic orbital? a) 1s b) 3d c) 2p d) 3f e) 6s

9.

How many electrons in an atom can have the quantum numbers n = 3, l = 2? a) 2 b) 5 c) 10 d) 18 e) 6

10. For each of the following sets quantum numbers, give the atomic orbital designation. n 2 3 4

l 1 0 2

ml 0 0 0

ms -½ +½ -½

a. 2p, 3s, 4d b. 2p, 4p, 4f c. 2s, 3d, 4p d. 2s, 4p, 4s e. 2s, 3p, 4d 11.

In a hydrogen atom, orbitals with the same energy: I) extend the same distance from the nucleus. II) have the same principle quantum number, n. III) are referred to as iso-electronic. IV) are referred to as degenerate. V) are represented by 1s and 2s orbitals. A) B) C) D) E)

12.

I, III, IV I, II, IV I, IV, V I, II, III I, II, III, and IV

The quantum numbers of the last electron of nickel could be: A) B) C) D) E)

n = 3, ℓ = 2, mℓ n = 4, ℓ = 2, mℓ n = 3, ℓ = 1, mℓ n = 3, ℓ = 2, mℓ n = 3, ℓ = 2, mℓ

= 0, ms = 1/2 = 0, ms = 1/2 = 0, ms = 1/2 = 0, ms = 0 = 1/2, ms = 1/2

13. An atom of fluorine contains nine electrons. How many of these electrons are in p orbitals? a) 2 b) 4 c) 5 d) 7 e) none 14. Of the following elements, which needs four electrons to complete its valence shell? a) Ba b) C c) Si d) P e) Cl

15. The number of unpaired electrons in the outer subshell of a S atom is a) 0 b) 1 c) 2 d) 3 e) none of these 16. a) b) c) d) e)

Which of the following electron configurations is correct? Ga: [Kr]4s23d104p1 Mo: [Kr]5s24d5 Ca: [Ar]4s13d10 Br: [Ar]4s23d104p5 Bi: [Xe]6s24f145d106p2

17. Select the correct electron configuration of Co3+ A) [Ar]4s2 3d7 B) [Ar]4s2 3d4 C) [Ar] 3d6 D) [Kr] 4s2 3d4 E) [Kr] 3d6 18. The complete electron configuration of antimony is a) 1s22s22p63s23p64s23d104p65s24d105d105p3 b) 1s22s22p63s23p64s23d104d104p3 c) 1s22s22p63s23p64s24p65s24d105d105p3 d) 1s22s22p63s23p64s23d104p65s24d105p2 e) none of these 19. An element with the electron configuration [Xe] 6s14f145d9 would belong to which class on the periodic table? a) rare earth elements b) alkaline earth elements c) halogens d) transition elements e) none of the above 20. Select the correct statement below: a) Phosphorous contains 10 core electrons and 5 valence electrons. Its orbital diagram contains one half-filled 3p orbital and two filled 3p orbitals. b) Aluminum contains 10 core electrons and 3 valence electrons. Its orbital diagram contains three half-filled 3p orbitals. c) Calcium contains 18 core electrons and 2 valence electrons. Its orbital diagram contains two half-filled 4s orbitals and no filled 4p orbitals. d) Sodium contains 10 core electrons and 1 valence electron. Its orbital diagram contains one half-filled 3p orbital and two empty 3p orbitals. e) None of the statements are correct.

21.

Select the correct statements below. I. An atom of chlorine is larger than sulfur because the addition of an electron increases the repulsions without an increase in attraction for the nucleus resulting in less screening. II. An atom of oxygen is smaller than an atom of carbon because the distance of the valence electrons remains the same while the attraction for the nucleus increases with increasing number of protons. III. An atom of potassium is smaller than an atom of rubidium because both effective nuclear charge increases down a group and the principal quantum number of the valence orbitals increases IV. An atom of sodium is smaller than an atom of magnesium because both effective nuclear charge increases down a group and the principal quantum number of the valence orbitals increases V. An atom of chlorine is smaller than an atom of bromine because the principal quantum number of the valence orbitals increases. VI. An atom of silicon is smaller than an atom of carbon because the principal quantum number of the valence orbitals increases. a) c)

II, IV, V only I, III, VI only

b) d)

II, V only I, III, IV, VI only

e)

22. In which group do all the elements have similar chemical properties? a) P, S, Cl b) Ag, Cd, Ar c) Na, Ca, Ba d) N, P, As

Only II

e) none

23. Order the elements S, Cl, and F in terms of increasing atomic radii. a) F, Cl, S b) Cl, F, S c) F, S, Cl d) S, Cl, F e) S, F, Cl 24. Select the correct statement. a) Na+ and K+,are isoelectronic because they both lost one electron and are in Group 1A. b) Ar and K+ are isoelectronic because they both have 18 electrons. c) Na and Mg are isoelectronic because they both are in the third period. d) Ca+ and Ca2+ are isoelectronic because they both are charged atoms of calcium and lost electrons. e) Cr2+ and Cu+ are isoelectronic because they both contain the same energy for electron affinity. 25. Which of the following arrangements is in order of increasing size? a) Ca2+ > K+ > Cl– > S2– b) Ca2+ < K+ < Cl– < S2– 2– – 2+ + c) S > Cl > Ca > K c) S2– < Cl– < K+ < Ca2+ e) 26

Ca2+ < S2– < Cl– < K+

Which of the following processes represents the ionization energy of bromine? a) Br(g)   Br+(g) + e– b) Br(l)   Br+(g) + e– e) Br2(g)   Br2+(g) c) Br(s)   Br+(g) + e– d) Br(s)   Br+(s) + e– – +e

27. a)

Order the elements S, Cl, and F in terms of decreasing ionization energy. S, Cl, F b) Cl, F, S c) F, S, Cl d) F, Cl, S e) S, F, Cl

28. a) b) c) d) e)

The second ionization energy of Mg is 1445 kJ/mol. The first ionization energy is 1445 kJ/mol less than 1445 kJ/mol greater than 1445 kJ/mol More information is needed to answer this question. None of these.

Consider the following electron configurations to answer questions 29 and 30 that follow: (i) 1s2 2s2 2p6 3s1 (ii) 1s2 2s2 2p6 3s2 (iii)1s2 2s2 2p6 3s2 3p1 (iv) 1s2 2s2 2p6 3s2 3p4 (v) 1s2 2s2 2p6 3s2 3p5 29.

The electron configuration belonging to the atom with the highest second ionization energy is ________. A) (i) B) (ii) C) (iii) D) (iv) E) (v)

30.

The electron configuration of the atom that has the most electron affinity is _______. A) (i) B) (ii) C) (iii) D) (iv) E) (v)

31. Of the following elements, which is most likely to form a negative ion with charge 2–? a) Ba b) Ca c) S d) P e) Cl 32.

Select which of the following are correctly identified. a) b) c) d) e)

Both CO and KBr are polar covalent molecules. Both MgO and HCl are ionic compounds. KBr is an ionic compound and I2 is a nonpolar covalent molecule. CO and H2 are nonpolar covalent molecules. HCl is a polar covalent molecule and NO is a nonpolar covalent molecule.

33. The electron-dot structure of the molecule, NH4O+, contains a. 1 double bond and 4 single bonds b. 5 single bonds and 3 lone pair electrons. c. 5 single bonds and 2 lone pair electrons. d. 5 single bonds and 1 lone pair electrons. e. 5 single bonds and zero lone pair electrons. 34.

A valid Lewis structure of ________ cannot be drawn without violating the octet rule. B) SO2 C) ICl5 D) SiF4 E) CO2 A) NI3

35.

In which of the following molecules would you expect the nitrogen-to-nitrogen bond to be the shortest? B) N2O4 C) N2 D) N2O E) NH3 A) N2H4

36. In the Lewis structure for ICl2–, what is the formal charge on Cl atom? a) -2 b) -1 c) 0 d) 1 e) 2 37. How many covalent bonds will be formed by bromine in BrO3– for the dot structure, where Br expands its octet to minimize formal charge (i.e., FC(Br) = 0), and as needed places negative formal charges on only the most electronegative atom(s). The Pauling electronegativity values are: Br = 2.8; O = 3.5. A) 3 B) 4 C) 5 D) 6 E) 7 38. Which formula is correctly matched with the number of -- valence electrons, covalent bonds, and lone pair electrons -- of the central atom (underlined)? a. SeH2; 6 valence electrons, 2 bonds, and 1 lone pair b. SiCl4; 4 valence electrons, 4 bonds, and 0 lone pairs c. FCl; 1 valence electron, 1 bond, and 0 lone pairs d. SCl2; 6 valence electrons, 2 bonds, and 0 lone pairs e. PH3; 4 valence electrons, 3 bonds, and 1 lone pair 39.

The electron-dot structure of the molecule, SF4, contains a. 1 double bond and 4 single bonds b. 4 single bonds and 13 lone pair electrons. c. 4 single bonds and 12 lone pair electrons. d. 4 single bonds and 1 lone pair electrons. e. 4 single bonds and zero lone pair electrons.

40. Which of the following compounds (or ions) contains an atom that does NOT follow the octet rule? a. BrF3 b. CBr4 c. NO+ d. BF4- e. NCl3 41.

There can be two equivalent best resonance structures of ________. A) NO2B) NO3C) SO32- D) SO42-

E) BrO3-

4 2 . Thee l e c t r onpa i ri naHFbondc oul dbec ons i de r e d a) closer to H because hydrogen has a larger radius and thus exerts greater control over the shared electron pair b) closer to F because fluorine has a higher electronegativity than hydrogen c) closer to H because hydrogen has a lower electronegativity than fluorine d) an inadequate model since the bond is ionic e) centrally located directly between the H and F 43. Consider the following statements concerning ionic bonding: I) Ionic bonding occurs between a metal, which has a high affinity for electrons, and a nonmetal, which loses electrons relatively easy. II) CaCl2 forms because Ca2+ is always a more stable species than the calcium atom alone. III) Compounds with ionic bonds tend to have low melting points.

IV) The electronegativity difference between the bonding atoms of ionic compounds is small since the electrons are not shared but rather held together by electrostatic forces. How many of these statement(s) is/are true concerning ionic bonding? A. B. C. D.

Only one statement is true Two of the statements are true Three of the statements are true All of the above statements are true. E. All of the above statements are false. 44. Which of the following bonds is least polar? a) C—O b) H—C c) P—Cl

d) Na—Cl

e) They are all nonpolar.

45. Select the answer choice that correct identifies if the bonds formed would be nonpolar covalent, polar covalent, or ionic. Try to use a periodic table when solving.

A) B) C) D) E)

C and F Nonpolar Polar Polar Polar Nonpolar

46. A) B) C) D) E)

Breaking bonds , while forming bonds . requires no energy; requires no energy releases energy; requires energy releases energy; releases energy requires energy; releases energy requires energy; requires energy

47.

Calculate the ∆Hrxn for this reaction using the given bond energies: CH4(g) + 2 H2O(g) → 4H2(g) + CO2(g) Bond Energy (kJ/mol) H-H 436 O-H 464 H-C 414

A)

-357 kJ

Ca and O Ionic Polar Ionic Polar Ionic

B) +170 kJ

N and N Nonpolar Nonpolar Nonpolar Ionic Nonpolar

C) -170 kJ

P and Cl Ionic Ionic Polar Nonpolar Polar

D) +357 kJ

K and Br Ionic Ionic Ionic Ionic Polar

E) -2110 kJ

C=O 799

48.

Estimate the enthalpy change for the reaction 2CO + O2  2CO2 given the following bond energies. BE(CO) = 1074 kJ/mol BE(O=O) = 499 kJ/mol BE(C=O) = 802 kJ/mol a) b) c) d) e)

+2380 kJ/mol +744 kJ/mol +1949 kJ/mol –561 kJ/mol –744 kJ/mol

49.

Resources GCU makes available to me so that I can be successful include:

a) b) c) d) e)

Access to Full-time faculty office hours, IA office hours, and Explore More Resource worksheets and key Study Guides Practice questions All of the above...