Chemistry 107 Exam 7-9 Good Luck!. a)7.1 x 10 –11 b)7.1 x 10 –2 c)1.3 x 10 27 d)1.4 x 10 10...

Chemistry 107

Exam 7-9Good Luck!

a) 7.1 x 10–11

b) 7.1 x 10–2

c) 1.3 x 1027

d) 1.4 x 1010

e) 7.1 x 10–18

1. Determine the wavelength (in nm) of an X-ray with a frequency of 4.2 x 1018

Hz.

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2. A major league pitcher throws a 148.8 g baseball at a speed of 92.5 mph (41.4 m/s). What is the de Broglie wavelength of the baseball in meters?

a) 4.81 x 10–38

b) 4.81 x 10– 41

c) 1.08 x 10– 34

d) 1.08 x 10– 37

e) 1.08 x 10– 40


3. An electron in a hydrogen atom in the n = 6 energy level emits 109.4 kJ/ mol of energy in a transition to a lower energy level. To what energy level does the electron fall?

a) 1

b) 2

c) 3

d) 4

e) 5


4. Which of the following transitions for an electron in a hydrogen atom would release the largest quantum of energy?

a) n = 3 → n = 1

b) n = 4 → n = 3

c) n = 1 → n = 4

d) n = 2 → n = 1


5. Which of the following is NOT an allowed set of quantum numbers?a) n = 4 l = 3 ml = 3

b) n = 1 l = 0 ml = 0

c) n = 5 l = 4 ml = – 2

d) n = 2 l = 1 ml = 0

e) n = 3 l = 3 ml = – 2


6. What is the frequency (Hz) of a infrared light that emits 24.5 kJ/ mol of energy?

a) 3.70x1034

b) 6.14x1013

c) 4.92x1019

d) 8.17x10–8

e) 2.70x10–35


7. Ultraviolet light emits a total of 2.5x10–17 J of light at a wavelength of 9.8x10–7 m. How many photons does this correspond to?

a) 1

b) 10

c) 25

d) 100

e) 125


8. Determine the wavelength (nm) of light absorbed when an electron in a hydrogen atom transitions from the n = 3 to the n = 5 energy level.

a) 434 nm

b) 656 nm

c) 684 nm

d) 780 nm

e) 1280 nm


9. The de Broglie wavelength of a 455 kg car is found to be 5.43x10–38 nm. Calculate the speed (m/ s) of the car.a) 26.8 m/ s

b) 37.3 m/ s

c) 2.68x10–8 m/ s

d) 3.73x107 m/ s

e) 3.00x108 m/ s


10. Which orbital is described by the following set of quantum numbers?

n = 3 l = 1 ml = –1

a) 1s

b) 2s

c) 3s

d) 3p

e) 3d


11. What is the ground state electron configuration for Mo?a) Mo: [Kr]5s24d4

b) Mo: [Kr]5s04d6

c) Mo: [Ar]4s23d4

d) Mo: [Ar]4s13d5

e) Mo: [Kr]5s14d5


12. Which of the following correctly illustrates the valence electron configuration of sulfur?

3s 3p

3s 3p

2s 2p

3s 3p

a)

b)

c)

d)


a) Ge b) Te c) Sn d) Se e) Sb

13. Which element’s 4+ ion would have the following electron configuration?

[Kr]4d10


a) Cl–

b) Ar

14. Consider the following isoelectronic series:

Cl– Ar K+ Ca2+

Which particle is the largest?

c) K+

d) Ca2+

e) All particles are the same size.


15. Consider the following successive ionization energies (kJ/mol):

a) Mg

b) Al

c) Si

d) P

e)S

IE1 IE2 IE3 IE4 IE5 IE6 IE7

1012 1900 2910 4960 6270 22,200 26,345

Which element in period three would most likely show this trend in ionization energies?


16. What is the ground state electron configuration for V?a) V: [Kr]4s33d2

b) V: [Kr]4s24d3

c) V: [Ar]4s23d3

d) V: [Ar]3d3

e) V: [Kr]4s24d3


a) Rb b) Sr c) Cs d) Ba e) Cl

17. Which element is the largest?


a) Sn b) Sn2+ c) Sn4+ d) Sn2+ and Sn4+ e) All are paramagnetic

18. Which of the following is diamagnetic?


a) K b) Ca c) Mg d) O e) F

19. Which element is the most non-metallic?


20. How many valence electrons does an atom of Sulfur possess?

a. 2 b. 3 c. 4 d. 5 e. 6


a. O b. F c. S d. Cl e. P

21. Which element has the greatest effective nuclear charge?


22. Which of the following sets gives the correct formal charges for the elements in the Lewis structure below?

a. S: –2 C: –4 N: –3

b. S: +6 C: +4 N: +5

c. S: –2 C: +4 N: –3

d. S: +1 C: 0 N: –1

e. S: 0 C: 0 N: –1

S C N


23. Rank the following in order of increasing bond polarity:

H─F H─Br F─F Na─Cl

a) H─F < H─Br < F─F < Na─Cl

b) F─F < H─F < H─Br < Na─Cl

c) H─Br < H─F < F─F < Na─Cl

d) F─F < H─Br < H─F < Na─Cl

e) Na─Cl < H─F < H─Br < F─F


24. Determine the formal charge of chlorine in the most stable Lewis structure for ClO2

–.

a. –2

b. –1

c. 0

d. +1

e. +2


25. Which of the following compounds has ionic bonding?

a. H2O

b. C6H12O6

c. NO2

d. Al

e. CaCO3


26. Use average bond energies to determine ΔHrxn for the burning of H2.

H2(g) + ½ O2(g) → H2O(g) a. 6 kJ

b. 470 kJ

c. –243 kJ

d. –350 kJ

e. –421 kJ

BondBond Energy

(kJ/mol)

H─H 436

O═O 498

O─O 142

O─H 464


27. Estimate the enthalpy change for the combustion of methanol, using bond energies.

a. -3454 kJ

b. 2652 kJ

c. -1426 kJ

d. 126 kJ

e. -802 kJ


28. Draw the Lewis structure for NO3

– . How many equivalent resonance structures can be drawn?

a. 1

b. 2

c. 3

d. 4

e. 5


29. Draw the best Lewis structure for Ca(OH)2. How many lone pairs of electrons are on Ca?

a. 0

b. 1

c. 2

d. 3

e. 4


The Answers• 1. B• 2. C• 3. C• 4. A• 5. E• 6. B• 7. E• 8. E• 9. A• 10. D• 11. E• 12. A• 13. B• 14. A• 15. D

• 16. C• 17. C• 18. D• 19. E• 20. E• 21. B• 22. E• 23. D• 24. C• 25. E• 26. C• 27. E• 28. C• 29. A

Chemistry 107 Exam 7-9 Good Luck!. a)7.1 x 10 –11 b)7.1 x 10 –2 c)1.3 x 10 27 d)1.4 x 10 10...

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Transcript of Chemistry 107 Exam 7-9 Good Luck!. a)7.1 x 10 –11 b)7.1 x 10 –2 c)1.3 x 10 27 d)1.4 x 10 10...