intro chemistry practice final

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PRACTICE FINAL Chem 6A-Tezcan Name: Student ID Number: Section Number: TA: Page 1

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Practice final for university level introductory chemistry

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Page 1: Intro Chemistry practice final

PRACTICE FINALChem 6A-Tezcan

Name: Student ID Number: Section Number: TA:

Page 1

Page 2: Intro Chemistry practice final

1. What is the amount of heat necessary to raise the temperature of 8.5 kg of water from 12.5°C to 84°C?

A) 3.0 x 103 kJ B) 36 J C) 2.5 x 103 kJ D) 2.5 x 106 kJ E) 25 kJ

2. Which of the following is likely to form ions two units lower in charge than expected from the group number?

A) Hg B) Cd C) Zn D) Ge E) Sb

3. The bond order of N22+ is A) 2.5. B) 1. C) 2. D) 1.5. E) 3.

4. 0.658 g of copper (I) chloride is diluted to the mark with water in a 50.0 mL volumetric flask. What is the molarity of the solution?

A) 1.32 x 10-2 M B) 0.133 M C) 9.79 x 10-2 M D) 0.294 M E) none of the above

5. Which of the following compounds is a strong electrolyte? A) HNO3

B) HNO2

C) NH3

D) H2O E) none of the above

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6. Consider the complete combustion of benzene (C6H6). What mass of H2O is produced when 25.0 g of benzene reacts with excess O2?

A) 150 g B) 17.3 g C) 0.114 g D) 76.2 g E) none of the above

7. Chlorine exists in two isotopes, 35Cl (atomic mass 34.969, 74.80% abundant) and 37Cl (atomic mass 36.966, 25.20% abundant). Based on these data, what is the average atomicmass of chlorine in g/mol?

A) 35.472! B) 35.698 C) 35.453 D) 34.969 E) none of the above

8. Which of the following is not planar? A) BCl3 B) ClF3

C) PCl3 D) XeF4

E) C2H4

9. A pollutant isolated from a drinking water sample contains only C, H, and O. Combustion analysis of a 4.00 g sample produces 1.367 g of water and 11.131 g of CO2. What could be the correct molecular formula for this compound?

A) C11H13O2

B) C3H3O C) C6H3O2

D) C10H6O2

E) none of the above

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10. In the direct reaction of silicon with Cl2 the yield of SiCl4 is 50%. How many grams of silicon must be reacted with excess chlorine in order to obtain 17 g SiCl4?

A) 1.4 g B) 2.8 g C) 5.6 g D) 17 g E) 28 g

11. How many unpaired electrons are in a manganese atom? A) 0 B) 5 C) 1 D) 4 E) 3

12. Predict the electronic configuration in the oxide ion in CaO. A) [He]2s22p6 or [Ne] B) [He]2s22p5

C) [He]2s22p63s2

D) [Ne]3s13p3

E) [Ne]3s23p3

13. A system expands in volume from 2.0 L to 24.5 L at constant temperature. Calculate the work (w) if the expansion occurs against a constant pressure of 5.00 atm.

A) -113 J B) 1.24 x 104 J C) -1.14 x 104 J D) 113 J E) 1.14 x 104 J

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14. The souring of wine occurs when oxygen reacts with ethanol to make acetic acid in the following balanced reaction:CH3CH2OH(aq) + O2(g) --> CH3CO2H(aq) + H2O(l)

If 75.00 g of ethanol and 0.26 g of O2 are sealed in a wine bottle, which is the limiting reactant for the oxidation reaction?

A) CH3CH2OH(aq) B) O2(g)

C) CH3CO2H(aq)

D) H2O(l)

E) none of the above

15. For dinitrogen monoxide, the arrangement of the atoms is N-N-O. In the Lewis structure with a double bond between NN and NO, the formal charges on N, N, and O, respectively, are

A) 0, –1, +1. B) –1, +1, 0. C) 0, +1, –1. D) 0, 0, 0. E) –2, +1, +1.

16. How many electrons, protons and neutrons are present in the carbon dioxide molecule, 15N18O2?

A) 22, 22, 27 B) 33, 33, 33 C) 23, 23, 28 D) 15, 15, 18 E) none of the above

17. Which of the following atoms has the highest electron affinity? A) Ar B) P C) Al D) Si

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18. Which of the following has bond angles slightly less than 120°? A) SO3

B) SF2

C) I3–

D) NO3–

E) O3

19. All of the following are polar except A) SF4.

B) ClO2–.

C) IF4+. D) XeF4. E) ClF3.

20. For the following Lewis structure, considering the atoms from left to right, the formal charges on S, C, and N, respectively, are

S C N-

A) 0, 0, -1 B) +1, +4, +5 C) 0, 1, -2 D) -1, 0, 0 E) -2, +4, -3

21. Combustion of a hydrocarbon will release more energy than combustion of an equal mass of carbohydrate because

A) the C-O and O-H single bonds in carbohydrates are weak. B) carbohydrates contain C-O and O-H bonds and hydrocarbons do not. C) the total energy of the C-C and C-H bonds in hydrocarbons is greater than the total

energy of the C=O and O-H bonds in the combustion products (carbon dioxide and water).

D) the total energy of the bonds in hydrocarbons is greater than the energy of the bonds in carbohydrates.

E) hydrocarbons have higher molar masses than carbohydrates.

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22. Use the Rydberg formula for atomic hydrogen to calculate the wavelength of a transition from n = 6 to n = 3.

A) 410 nm B) 1094 nm C) 547 nm D) 1.8 x 10-10 nm E) none of the above

23. Write three Lewis structures for the cyanate ion, NCO–, where the arrangement of atoms is N-C-O. In the most plausible structure,

A) there is a triple bond between N and C. B) there are two double bonds. C) there is a triple bond between C and O. D) the formal charge on O is +1. E) the formal charge on N is –1.

24. A gas is allowed to expand at constant temperature from a volume of 2.0 L to 11.2 L against an external pressure of 0.750 atm. If the gas absorbs 128 J of heat from the surroundings, what are the values of q, w, and ΔE, respectively?

A) 128 J, 6.9 J, 135 J B) 128 J, -6.9 J, 121 J C) 128 J, 697 J, 825 J D) 128 J, -697 J, -569 J E) -128 J, -6.9 J, -135 J

25. The three quantum numbers for an electron in a hydrogen atom in a certain state are n = 4, l = 1, ml = 1. The electron is located in what type of orbital?

A) 4s B) 3p C) 3d D) 4d E) 4p

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26. Three isotopic peaks are observed in the mass spectrum of a sample of dilithium molecules, Li2. How many isotopes of Li are present in the sample?

A) 1 B) 2 C) 3 D) 4 E) 5

27. The oxidation state of vanadium in Rb4Na[HV10O28] is: A) -6 B) +8 C) -5 D) +3 E) +5

28. Which of the following statements is true? A) A p-electron penetrates more than an s-electron through the inner shells of an atom. B) A p-electron penetrates less than a d-electron through the inner shells of an atom. C) A p-electron has a nonzero probability density at the nucleus. D) A d-electron has a nonzero probability density at the nucleus. E) A p-electron experiences a smaller effective nuclear charge than an s-electron.

29. When aqueous solutions of FeCl2 and AgNO3 are mixed, which of the following equations is balanced and correctly represents the resulting reaction?

A) FeCl2 (aq) + AgNO3 (aq) -> Fe(s) + AgNO3 (aq)

B) FeCl2 (aq) + AgNO3 (aq) -> Fe(NO3)2 (aq) + 2 AgCl (s)

C) FeCl2 (aq) + 2 AgNO3 (aq) -> Fe(NO3)2 (aq) + 2 AgCl (s)

D) FeCl2 (aq) + AgNO3 (aq) -> Fe(NO3)2 (aq) + AgCl (s)

E) FeCl2 (aq) + 2 AgNO3 (aq) -> Fe(NO3)2 (aq) + AgCl (s)

30. For the ground-state ion Bi3+, what type of orbital do the electrons with highest energy reside in?

A) 5d B) 6s C) 4f D) 5p E) 6p

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31. Consider the balanced reaction:5 NaN3(s)+ NaNO3(aq) -> 3 Na2O(s) + 8 N2(g)

If 5.00 g of NaN3(s) are reacted with excess NaNO3 and 3.30 g of N2(g) are produced, what is the percent yield of the reaction?

A) 95.7% B) 66.0% C) 62.5% D) 100% E) none of the above

32. How many lone pairs of electrons are found in the Lewis structure of urea, (NH2)2CO? A) 2 B) 3 C) 6 D) 4 E) 8

33. Which of the following salts has the highest melting point? A) KCl B) KI C) RbF D) KBr E) KF

34. Which of the following species has bonds with the most ionic character? A) SiO2

B) PCl3 C) P4O10

D) CO2

E) NO2

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35. Which of the following statements regarding electromagnetic radiation is true? A) Electromagnetic radiation with a wavelength of 400 nm travels faster than that with a

wavelength of 600 nm. B) The frequency of electromagnetic radiation determines how fast it travels. C) Electromagnetic radiation with a wavelength of 400 nm has a frequency that is smaller

than that with a wavelength of 600 nm. D) Electromagnetic radiation with a wavelength of 600 nm travels faster than that with a

wavelength of 400 nm. E) Electromagnetic radiation with a wavelength of 600 nm has a frequency that is smaller

than that with a wavelength of 400 nm.

36. What is the shape of IF4+? A) tetrahedral B) seesaw C) trigonal bipyramidal D) square planar E) T-shaped

37. The number of grams of Fe in 50.00 g of Fe2O3 is A) 5585 g B) 17.49 g C) 0.6260 g D) 34.97 g E) 41.23 g

38. Consider the reaction:CuO(s) + C(s) --> Cu(s) + CO2(g)

Identify the oxidizing agent. A) Cu! B) CuO C) CO2

D) C E) none of the above

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39. Estimate the frequency of the electromagnetic wave shown below.

A) 1.5 × 1017 s–1

B) 3.0 × 1017 s–1

C) 1.0 × 1017 s–1

D) 2.0 × 1017 s–1

E) Not enough information is given to permit calculation of the frequency.

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40. Which Lewis structure of chlorate shown below has the most stable distribution of formal charges?

A)

OClOO

-

B)

OClOO

-

C)

OClOO

-

D)

O

ClO

O

-

E)

O

ClO

O

-

41. An aqueous solution labeled "tin (II) sulfite" contains the ions: A) Ti2+ and S2-

B) Ti2+ and SO32-

C) Sn2+ and SO32-

D) Sn2+ and SO42-

E) Sn2+ and S2-

42. Which one of the following reactions occurring at 25°C is the formation reaction of H2SO4(l)?

A) H2(g) + S(s) + 2 O2(g) -> H2SO4(l)

B) H2SO4(l) -> H2(g) + S(s) + 2 O2(g)

C) H2(g) + S(g) + 2 O2(g) -> H2SO4(l)

D) H2SO4(l) -> 2 H(g) + S(s) + 4 O(g)

E) 2 H(g) + S (g) + 4 O(g) -> H2SO4(l)

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43. Predict the electronic configuration in the oxide ion in CaO. A) [He]2s22p6 or [Ne] B) [He]2s22p5

C) [He]2s22p63s2

D) [Ne]3s13p3

E) [Ne]3s23p3

44. During a titration the following data were collected. A 20.0 mL portion of solution of an unknown acid HX was titrated with 2.0 M KOH. It required 60.0 mL of the base to neutralize the sample. What is the molarity of the acid HX?

A) 6.0 M B) 0.67 M C) !3.0 M D) 0.12 M E) none of the above

45. The total number of orbitals in a shell with principal quantum number 5 is A) 32. B) 50. C) 25. D) 40. E) 5.

46. Which of the following has the smallest atomic radius? A) Cl B) P C) S D) Si E) Al

47. Write the ground-state electron configuration of a tin(IV) ion. A) [Kr]4d35s15p6

B) [Kr]4d45p6

C) [Kr]4d55s25p3

D) [Kr]4d55p5

E) [Kr]4d10

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48. The energy of a C-O bond is about 360 kJ/mol. What is the maximum wavelength of a photon of light that can break a single C-O bond?

A) 5.5 x 10-31 nm B) 330 nm C) 410 nm D) 6.0 x 10-10 nm

E) none of the above

49. Which of the following species is isoelectronic with Kr? A) K+

B) Cl– C) Ar D) Xe E) Sr2+

50. Which compound below contains 52.9% Br by mass? A) NaBr! B) NaBrO C) NaBrO2

D) NaBrO3

E) NaBrO4

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