General Organic And Biological Chemistry Structures of Life, 5th Edition By Timberlake – Test Bank A+

Description

6.1 Multiple-Choice Questions

1) The number of valence electrons found in an atom of a Group A element is equal to

1. A) its atomic number.
2. B) its mass number.
3. C) its group number.
4. D) eight.
5. E) eight minus the group number.

Answer: C

Objective: 6.1

Global Outcomes: GO4

2) Valence electrons are electrons located

1. A) in the outermost energy level of an atom.
2. B) in the nucleus of an atom.
3. C) in the innermost energy level of an atom.
4. D) throughout the atom.
5. E) in the first three shells of an atom.

Answer: A

Objective: 6.1

Global Outcomes: GO4

3) In an electron-dot structure of an element, the dots are used to represent

1. A) all of the electrons in the atom.
2. B) the valence electrons.
3. C) the electron arrangement.
4. D) only the electrons that will participate in bond formation.
5. E) the electrons that the element will gain when it forms a compound.

Answer: B

Objective: 6.1

Global Outcomes: GO4

4) How many valence electrons are in the electron-dot structures for the elements in group 3A(13)?

1. A) 1
2. B) 2
3. C) 3
4. D) 4
5. E) 6

Answer: C

Objective: 6.1

Global Outcomes: GO4

5) How many valence electrons does nitrogen have?

1. A) one
2. B) two
3. C) three
4. D) four
5. E) five

Answer: E

Objective: 6.1

Global Outcomes: GO4

6) How many valence electrons does carbon have?

1. A) one
2. B) two
3. C) three
4. D) four
5. E) five

Answer: D

Objective: 6.1

Global Outcomes: GO4

7) The octet rule indicates that

1. A) all of the noble gases have eight total electrons.
2. B) all of the shells in an atom hold a maximum of 8 electrons.
3. C) all of the Group A elements have 8 valence electrons.
4. D) atoms lose, gain, or share valence electrons to have 8 valence electrons.
5. E) the noble gases react with other compounds to get 8 valence electrons.

Answer: D

Objective: 6.1

Global Outcomes: GO4

8) In ionic compounds, ________ lose their valence electrons to form positively charged ________. (5,2)

1. A) metals; anions
2. B) nonmetals; cations
3. C) metals; polyatomic ions
4. D) nonmetals; anions
5. E) metals; cations

Answer: E

Objective: 6.1

Global Outcomes: GO4

9) How many electrons will aluminum gain or lose when it forms an ion?

1. A) lose 1
2. B) gain 5
3. C) lose 2
4. D) lose 3
5. E) gain 1

Answer: D

Objective: 6.1

Global Outcomes: GO4

10) What is the symbol for the ion with 19 protons and 18 electrons?

1. A) F+
2. B) F-
3. C) Ar+
4. D) K-
5. E) K+

Answer: E

Objective: 6.1

Global Outcomes: GO4

11) To form an ion, a sodium atom

1. A) gains one electron.
2. B) gains two electrons.
3. C) loses seven electrons.
4. D) loses one electron.
5. E) loses two electrons.

Answer: D

Objective: 6.1

Global Outcomes: GO4

12) An anion always

1. A) has a positive charge.
2. B) contains a group of two or more atoms with a positive charge.
3. C) contains a metal and a nonmetal.
4. D) forms covalent bonds.
5. E) has a negative charge.

Answer: E

Objective: 6.1

Global Outcomes: GO4

13) What is the ionic charge of an ion with 13 protons and 10 electrons?

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

Answer: C

Objective: 6.1

Global Outcomes: GO4

14) The number of electrons in an ion with 20 protons and an ionic charge of 2+ is

1. A) 24.
2. B) 22.
3. C) 20.
4. D) 18.
5. E) 16.

Answer: D

Objective: 6.1

Global Outcomes: GO4

15) Elements in group 2A(2) of the periodic table form ions with a charge of

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

Answer: C

Objective: 6.1

Global Outcomes: GO4

16) The ion of aluminum is

1. A) Al+.
2. B) Al2+.
3. C) Al3+.
4. D) Al3-.
5. E) Al2-.

Answer: C

Objective: 6.1

Global Outcomes: GO4

17) How many electrons will chlorine gain or lose when it forms an ion?

1. A) lose 1
2. B) gain 1
3. C) lose 7
4. D) gain 2
5. E) lose 3

Answer: B

Objective: 6.1

Global Outcomes: GO4

18) What is the correct formula for the oxide ion?

1. A) O2-
2. B) O-
3. C) O+
4. D) O2+
5. E) O3+

Answer: A

Objective: 6.1

Global Outcomes: GO4

19) What is the formula of the nitride ion?

1. A) N3-
2. B) NO2-
3. C) NO33-
4. D) NO32-
5. E) NO3-

Answer: A

Objective: 6.1

Global Outcomes: GO4

20) How many electrons will lithium gain or lose when it forms an ion?

1. A) lose 1
2. B) gain 5
3. C) lose 2
4. D) lose 3
5. E) gain 1

Answer: A

Objective: 6.1

Global Outcomes: GO4

21) How many electrons will iodine gain or lose when it forms an ion?

1. A) lose 1
2. B) gain 5
3. C) lose 2
4. D) lose 3
5. E) gain 1

Answer: E

Objective: 6.1

Global Outcomes: GO4

22) An ionic compound

1. A) has a net positive charge.
2. B) has a net negative charge.
3. C) contains only cations.
4. D) contains only anions.
5. E) has a net charge of zero.

Answer: E

Objective: 6.2

Global Outcomes: GO2

23) The correct formula for a compound formed from the elements Al and O is

1. A) AlO.
2. B) Al2
3. C) Al3O2.
4. D) AlO3.
5. E) Al2O3.

Answer: E

Objective: 6.2

Global Outcomes: GO2

24) The correct formula for the compound formed from Mg and S is

1. A) MgS.
2. B) MgS2.
3. C) Mg2
4. D) Mg2S2.
5. E) Mg2S3.

Answer: A

Objective: 6.2

Global Outcomes: GO2

25) Which one of the following compounds contains an ion with a 3+ charge?

1. A) KCl
2. B) Na2O
3. C) FeCl3
4. D) CuCl
5. E) MgCl2

Answer: C

Objective: 6.2

Global Outcomes: GO2

26) The compound MgCl2 is named

1. A) magnesium chlorine.
2. B) magnesium dichloride.
3. C) magnesium(II) chloride.
4. D) magnesium chloride.
5. E) dimagnesium chloride.

Answer: D

Objective: 6.3

Global Outcomes: GO2

27) Which one of the following elements forms two or more ions with different ionic charges?

1. A) K
2. B) F
3. C) Ca
4. D) O
5. E) Fe

Answer: E

Objective: 6.3

Global Outcomes: GO2

28) What is the correct formula for the iron(II) ion?

1. A) Fe+
2. B) Fe2+
3. C) Fe3+
4. D) Fe2-
5. E) Fe3-

Answer: B

Objective: 6.3

Global Outcomes: GO2

29) The name of the Cu+ ion is

1. A) copper(II).
2. B) copper(I).
3. C) cobalt.
4. D) copper.
5. E) cuprum.

Answer: B

Objective: 6.3

Global Outcomes: GO2

30) What is the correct formula for iron(III) sulfide?

1. A) Fe2S2
2. B) Fe2S
3. C) FeS
4. D) FeS2
5. E) Fe2S3

Answer: E

Objective: 6.3

Global Outcomes: GO2

31) The name of Al2(SO4)3 is

1. A) aluminum(III) sulfate.
2. B) dialuminum trisulfate.
3. C) dialuminum sulfate.
4. D) dialuminum trisulfide.
5. E) aluminum sulfate.

Answer: E

Objective: 6.3

Global Outcomes: GO2

32) The name of PbO2 is

1. A) lead dioxide.
2. B) lead(II) oxide.
3. C) lead(IV) oxide.
4. D) plumbum oxide.
5. E) lead oxygen.

Answer: C

Objective: 6.3

Global Outcomes: GO2

33) The formula of copper(I) sulfide is

1. A) CuS.
2. B) Cu2
3. C) Cu2(SO4)3.
4. D) CuSO4.
5. E) CuS2.

Answer: B

Objective: 6.3

Global Outcomes: GO2

34) A group of covalently bonded atoms that has an overall electrical charge is called a(n)

1. A) ionic compound.
2. B) anion.
3. C) polyatomic ion.
4. D) cation.
5. E) molecule.

Answer: C

Objective: 6.4

Global Outcomes: GO2

35) Which of the following polyatomic ions has a positive charge?

1. A) hydroxide
2. B) sulfate
3. C) hydrogen carbonate
4. D) ammonium
5. E) nitrate

Answer: D

Objective: 6.4

Global Outcomes: GO2

36) The name of the HSO4- ion is

1. A) sulfate.
2. B) hydrogen sulfate.
3. C) sulfite.
4. D) hydrogen sulfite.
5. E) sulfide.

Answer: B

Objective: 6.4

Global Outcomes: GO2

37) What is the formula of a compound that contains Na+ and PO43- ions?

1. A) Na3PO4
2. B) NaPO4
3. C) Na2PO3
4. D) Na3PO3
5. E) Na3P

Answer: A

Objective: 6.4

Global Outcomes: GO2

38) Fe2(SO4)3 is called

1. A) iron sulfate.
2. B) iron(II) sulfate.
3. C) iron(III) sulfate.
4. D) diiron trisulfate.
5. E) iron trisulfate.

Answer: C

Objective: 6.4

Global Outcomes: GO2

39) What is the formula for aluminum nitrite?

1. A) Al2NO2
2. B) AlNO3
3. C) Al(NO2)3
4. D) Al2(NO3)3
5. E) Al2(NO2)2

Answer: C

Objective: 6.4

Global Outcomes: GO2

40) Which of the following polyatomic ions has a 3- ionic charge?

1. A) hydroxide
2. B) nitrate
3. C) sulfate
4. D) phosphate
5. E) bicarbonate

Answer: D

Objective: 6.4

Global Outcomes: GO2

41) A(n) ________ is the smallest neutral unit of two or more atoms held together by a covalent bond.

1. A) ionic compound
2. B) nucleus
3. C) molecule
4. D) formula
5. E) unit

Answer: C

Objective: 6.5

Global Outcomes: GO2

42) In a molecule with covalent bonding

1. A) oppositely charged ions are held together by strong electrical attractions.
2. B) atoms of metals form bonds to atoms of nonmetals.
3. C) atoms of different metals form bonds.
4. D) atoms are held together by sharing electrons.
5. E) atoms of noble gases are held together by attractions between oppositely charged ions.

Answer: D

Objective: 6.5

Global Outcomes: GO2

43) The correct name of the compound is

1. A) nitrogen chloride.
2. B) trinitrogen chloride.
3. C) nitrogen(III) chloride.
4. D) nickel chloride.
5. E) nitrogen trichloride.

Answer: E

Objective: 6.5

Global Outcomes: GO2

44) The formula for a molecule formed from N and Cl would be

1. A) NCl.
2. B) NCl2.
3. C) NCl3.
4. D) N3
5. E) NCl5.

Answer: C

Objective: 6.5

Global Outcomes: GO2

45) The types of compounds that use prefixes in their names are

1. A) ionic compounds.
2. B) ionic compounds involving transition metals.
3. C) polyatomic ions.
4. D) covalent compounds.
5. E) compounds that contain polyatomic ions.

Answer: D

Objective: 6.5

Global Outcomes: GO2

46) The correct name for the compound N2O3 is

1. A) nitrogen oxide.
2. B) nitrogen trioxide.
3. C) dinitride trioxide.
4. D) dinitrogen oxide.
5. E) dinitrogen trioxide.

Answer: E

Objective: 6.5

Global Outcomes: GO2

47) What is the formula of carbon tetraiodide?

1. A) CI
2. B) CI4
3. C) C4I
4. D) CI3
5. E) C2I4

Answer: B

Objective: 6.5

Global Outcomes: GO2

48) Which of the following elements does NOT exist as a diatomic molecule?

1. A) hydrogen
2. B) nitrogen
3. C) chlorine
4. D) oxygen
5. E) carbon

Answer: E

Objective: 6.6

Global Outcomes: GO2

49) In a covalently bonded molecule, the number of electrons that an atom shares with others is usually equal to the number of electrons

1. A) in the atom.
2. B) in its nucleus.
3. C) in all the atoms.
4. D) in its ion.
5. E) needed to give it a stable electron configuration.

Answer: E

Objective: 6.6

Global Outcomes: GO2

50) Double and triple bonds form because

1. A) the atoms involved have high electronegativities.
2. B) single covalent bonds do not give all of the atoms in the molecule eight valence electrons.
3. C) one of the atoms in the molecule has more than eight valence electrons.
4. D) the ions involved have charges larger than one.
5. E) there is at least one hydrogen atom involved in the bond.

Answer: B

Objective: 6.6

Global Outcomes: GO2

51) How many valence electrons are in the electron-dot structure of H2O?

1. A) 2
2. B) 4
3. C) 6
4. D) 8
5. E) 10

Answer: D

Objective: 6.6

Global Outcomes: GO2

52) How many lone pairs of electrons are in the electron-dot structure of H2O?

1. A) 0
2. B) 1
3. C) 2
4. D) 3
5. E) 4

Answer: C

Objective: 6.6

Global Outcomes: GO2

53) Choose the best electron-dot structure for OCl2.

A)

B)

C)

D)

E)

Answer: E

Objective: 6.6

Global Outcomes: GO2

54) Choose the best electron-dot structure for CH2Cl2.

A)

B)

C)

D)

E)

Answer: B

Objective: 6.6

Global Outcomes: GO2

55) How many valence electrons are in the electron-dot structure of CCl4?

1. A) 0
2. B) 82
3. C) 6
4. D) 8
5. E) 32

Answer: E

Objective: 6.6

Global Outcomes: GO2

56) The ability of an atom to attract the shared electrons in a covalent bond is its

1. A) electronegativity.
2. B) bonding ability.
3. C) polarity.
4. D) ionic character.
5. E) nonpolarity.

Answer: A

Objective: 6.7

Global Outcomes: GO2

57) Which of the following substances contains a nonpolar covalent bond?

1. A) H2O
2. B) NaCl
3. C) NH3
4. D) MgF2
5. E) N2

Answer: E

Objective: 6.7

Global Outcomes: GO2

58) Which of the following elements has the lowest electronegativity?

1. A) Li
2. B) C
3. C) N
4. D) O
5. E) F

Answer: A

Objective: 6.7

Global Outcomes: GO2

59) Which of the following compounds contains a polar covalent bond?

1. A) NaF
2. B) HCl
3. C) Br2
4. D) MgO
5. E) O2

Answer: B

Objective: 6.7

Global Outcomes: GO2

60) Which of the following compounds contains an ionic bond?

1. A) NH3
2. B) H2O
3. C) CaO
4. D) H2
5. E) CH4

Answer: C

Objective: 6.7

Global Outcomes: GO2

61) If the electronegativity difference between elements X and Y is 2.1, the bond between the elements X-Y is

1. A) ionic.
2. B) nonpolar ionic.
3. C) nonpolar covalent.
4. D) polar covalent.
5. E) impossible.

Answer: A

Objective: 6.7

Global Outcomes: GO2

62) Ionic bonding is expected in which of these compounds?

1. A) Cl2
2. B) KF
3. C) OF2
4. D) HF
5. E) H2

Answer: B

Objective: 6.7

Global Outcomes: GO2

63) A polar covalent bond is found in which of these compounds?

1. A) H2O
2. B) F2
3. C) NaCl
4. D) H2
5. E) N2

Answer: A

Objective: 6.7

Global Outcomes: GO2

64) The bond in Cl2 is a(n)

1. A) ionic bond.
2. B) nonpolar covalent bond.
3. C) metallic bond.
4. D) polar ionic bond.
5. E) no bond.

Answer: B

Objective: 6.7

Global Outcomes: GO2

65) The VSEPR theory allows us to determine the most favorable

1. A) shape of a molecule.
2. B) charge on an ion.
3. C) color of a compound.
4. D) bond type for a molecule.
5. E) formula for a compound.

Answer: A

Objective: 6.8

Global Outcomes: GO2

66) The shape of the carbon tetrachloride molecule is

1. A) linear.
2. B) square.
3. C) pyramidal.
4. D) tetrahedral.
5. E) octagonal.

Answer: D

Objective: 6.8

Global Outcomes: GO2

67) The water molecule has a dipole with the negative portion

1. A) localized between the hydrogen atoms.
2. B) pointing toward the oxygen atom.
3. C) localized on one of the hydrogens.
4. D) pointing from the oxygen through the hydrogen atoms.
5. E) surrounding the molecule.

Answer: B

Objective: 6.8

Global Outcomes: GO2

68) The shape of the ammonia molecule ( NH3) is

1. A) linear.
2. B) square.
3. C) pyramidal.
4. D) hexagonal.
5. E) octagonal.

Answer: C

Objective: 6.8

Global Outcomes: GO2

69) The shape of the carbon dioxide (CO2) is

1. A) linear.
2. B) square.
3. C) pyramidal.
4. D) hexagonal.
5. E) bent.

Answer: A

Objective: 6.8

Global Outcomes: GO2

70) The shape of the water molecule ( H2O) is

1. A) linear.
2. B) tetrahedral.
3. C) pyramidal.
4. D) bent.
5. E) octagonal.

Answer: D

Objective: 6.8

Global Outcomes: GO2

71) The carbon tetrachloride molecule, CCl4, has the shape of a

1. A) tetrahedron.
2. B) square.
3. C) cube.
4. D) circle.
5. E) sphere.

Answer: A

Objective: 6.8

Global Outcomes: GO2

72) Hydrogen sulfide, H2S, has a shape similar to

1. A) carbon dioxide.
2. B) carbon monoxide.
3. C) hydrogen chloride.
4. D) water.
5. E) carbon tetrachloride.

Answer: D

Objective: 6.8

Global Outcomes: GO2

73) The carbon tetrachloride molecule, CCl4, is

1. A) a polar molecule with polar bonds.
2. B) a nonpolar molecule with polar bonds.
3. C) a nonpolar molecule with nonpolar bonds.
4. D) a polar molecule with nonpolar bonds.
5. E) a polar molecule with ionic bonds.

Answer: B

Objective: 6.8

Global Outcomes: GO2

74) The ammonia molecule ( NH3) is

1. A) a polar molecule with polar bonds.
2. B) a nonpolar molecule with polar bonds.
3. C) a nonpolar molecule with nonpolar bonds.
4. D) a polar molecule with nonpolar bonds.
5. E) a polar molecule with ionic bonds.

Answer: A

Objective: 6.8

Global Outcomes: GO2

75) The strongest interactions between molecules of ammonia ( NH3) are

1. A) ionic bonds.
2. B) hydrogen bonds.
3. C) polar covalent.
4. D) dipole-dipole.
5. E) dispersion forces.

Answer: B

Objective: 6.9

Global Outcomes: GO2

76) The strongest interactions between molecules of hydrogen ( H2) are

1. A) ionic bonds.
2. B) hydrogen bonds.
3. C) polar covalent.
4. D) dipole-dipole.
5. E) dispersion forces.

Answer: E

Objective: 6.9

Global Outcomes: GO2

77) The strongest interactions between molecules of hydrogen chloride are

1. A) ionic bonds.
2. B) covalent bonds.
3. C) hydrogen bonds.
4. D) dipole-dipole interactions.
5. E) dispersion forces.

Answer: D

Objective: 6.9

Global Outcomes: GO2

78) The strongest interactions between molecules of iodine I2 are examples of

1. A) ionic bonds.
2. B) covalent bonds.
3. C) hydrogen bonds.
4. D) dipole-dipole interactions.
5. E) dispersion forces.

Answer: E

Objective: 6.9

Global Outcomes: GO2

79) The strongest interactions in the compound sodium fluoride, NaF, are examples of

1. A) ionic bonds.
2. B) covalent bonds.
3. C) hydrogen bonds.
4. D) dipole-dipole interactions.
5. E) dispersion forces.

Answer: A

Objective: 6.9

Global Outcomes: GO2

80) The strongest interactions between atoms of helium He are examples of

1. A) ionic bonds.
2. B) covalent bonds.
3. C) hydrogen bonds.
4. D) dipole-dipole interactions.
5. E) dispersion forces.

Answer: E

Objective: 6.9

Global Outcomes: GO2

6.2 Short Answer Questions

Identify each of the following molecules as polar or nonpolar.

1) carbon tetrachloride

Answer: nonpolar

Objective: 6.8

Global Outcomes: GO2

2) water

Answer: polar

Objective: 6.8

Global Outcomes: GO2

3) carbon dioxide

Answer: nonpolar

Objective: 6.8

Global Outcomes: GO2

4) hydrogen sulfide

Answer: polar

Objective: 6.8

Global Outcomes: GO2

5) hydrogen fluoride

Answer: polar

Objective: 6.8

Global Outcomes: GO2

6) carbon monoxide

Answer: polar

Objective: 6.8

Global Outcomes: GO2

Identify each of the following compounds as covalent or ionic.

7) nitrogen trichloride

Answer: covalent

Objective: 6.6

Global Outcomes: GO2

8) carbon tetrachloride

Answer: covalent

Objective: 6.6

Global Outcomes: GO2

9) potassium oxide

Answer: ionic

Objective: 6.6

Global Outcomes: GO2

10) carbon dioxide

Answer: covalent

Objective: 6.6

Global Outcomes: GO2

11) sodium fluoride

Answer: ionic

Objective: 6.6

Global Outcomes: GO2

12) hydrogen sulfide

Answer: covalent

Objective: 6.6

Global Outcomes: GO2

13) The weakest type of force between particles of a substance is termed ________.

Answer: dispersion forces

Objective: 6.9

Global Outcomes: GO2

14) Are hydrogen bonds stronger or weaker than covalent bonds?

Answer: weaker

Objective: 6.9

Global Outcomes: GO2

15) Are dipole-dipole interactions weak or strong compared to ionic bonds?

Answer: weak

Objective: 6.9

Global Outcomes: GO2

16) What is the name of Na2S?

Answer: sodium sulfide

Objective: 6.3

Global Outcomes: GO2

17) What is the name of FeCl3?

Answer: iron(III) chloride

Objective: 6.3

Global Outcomes: GO2

18) What is the name of SF6?

Answer: sulfur hexafluoride

Objective: 6.5

Global Outcomes: GO2

6.3 Matching Questions

Match the correct name of the polyatomic ions with the formulas given.

1. A) hydrogen sulfate
2. B) nitrite
3. C) hydroxide
4. D) carbonate
5. E) phosphite
6. F) sulfate
7. G) oxide
8. H) hydrogen carbonate
9. I) nitrate
10. J) hydrogen sulfite
11. K) phosphate
12. L) carbonite
13. M) sulfite

1) NO3-

Objective: 6.4

Global Outcomes: GO2

2) CO32-

Objective: 6.4

Global Outcomes: GO2

3) SO42-

Objective: 6.4

Global Outcomes: GO2

4) SO32-

Objective: 6.4

Global Outcomes: GO2

5) PO43-

Objective: 6.4

Global Outcomes: GO2

6) NO2-

Objective: 6.4

Global Outcomes: GO2

7) HCO3-

Objective: 6.4

Global Outcomes: GO2

8) HSO4-

Objective: 6.4

Global Outcomes: GO2

9) OH-

Objective: 6.4

Global Outcomes: GO2

Answers: 1) I 2) D 3) F 4) M 5) K 6) B 7) H 8) A 9) C

Give the correct charge for ions of the following elements.

1. A) 1-
2. B) 2-
3. C) 1+
4. D) 0
5. E) 2+
6. F) 3+

10) Ca

Objective: 6.1

Global Outcomes: GO2

11) Cl

Objective: 6.1

Global Outcomes: GO2

12) O

Objective: 6.1

Global Outcomes: GO2

13) Al

Objective: 6.1

Global Outcomes: GO2

14) K

Objective: 6.1

Global Outcomes: GO2

Answers: 10) E 11) A 12) B 13) F 14) C

Indicate the type of bonding you would expect between the following elements.

1. A) none
2. B) polar covalent
3. C) nonpolar covalent
4. D) ionic

15) Na and F

Objective: 6.7

Global Outcomes: GO2

16) N and F

Objective: 6.7

Global Outcomes: GO2

17) F and F

Objective: 6.7

Global Outcomes: GO2

18) He and F

Objective: 6.7

Global Outcomes: GO2

19) H and F

Objective: 6.7

Global Outcomes: GO2

Answers: 15) D 16) B 17) C 18) A 19) B

Match the chemical name with the correct formula.

1. A) MgSO3
2. B) MgSO4
3. C) MgS
4. D) Mg(HSO4)2
5. E) Mg(HSO3)2

20) magnesium sulfate

Objective: 6.4

Global Outcomes: GO2

21) magnesium hydrogen sulfate

Objective: 6.4

Global Outcomes: GO2

22) magnesium sulfide

Objective: 6.4

Global Outcomes: GO2

23) magnesium sulfite

Objective: 6.4

Global Outcomes: GO2

24) magnesium hydrogen sulfite

Objective: 6.4

Global Outcomes: GO2

Answers: 20) B 21) D 22) C 23) A 24) E

General, Organic & Biological Chemistry, 5e (Timberlake)

Chapter 7 Chemical Reactions and Quantities

7.1 Multiple-Choice Questions

1) A chemical equation is balanced when

1. A) the total number of molecules is the same in reactants and products.
2. B) the total number of ions is the same in reactants and products.
3. C) the sum of the coefficients of the reactants is equal to the sum of the coefficients of the products.
4. D) the number of atoms of each element is the same in reactants and products.
5. E) the charge on each atom is the same in reactants and products.

Answer: D

Objective: 7.1

Global Outcomes: GO2

2) In any balanced chemical equation, the number of each type of atom on both sides of the equation is

1. A) doubled.
2. B) the same.
3. C) decreased by one.
4. D) increased by one.
5. E) dependent on the temperature.

Answer: B

Objective: 7.1

Global Outcomes: GO2

3) Which of the following gives the balanced equation for this reaction?

K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + KNO3

1. A) KPO4+ CaNO3+ KNO3
2. B) K3PO4+ Ca(NO3)2→ Ca3(PO4)2 + 3KNO3
3. C) 2K3PO4+ Ca(NO3)2→ Ca3(PO4)2 + 6KNO3
4. D) 2K3PO4+ 3Ca(NO3)2→ Ca3(PO4)2 + 6KNO3
5. E) K3PO4+ Ca(NO3)2→ Ca3(PO4)2 + KNO3

Answer: D

Objective: 7.1

Global Outcomes: GO2

4) Which of the following correctly gives the best coefficients for the reaction below?

N2H4 + H2O2 → N2 + H2O

1. A) 1, 1, 1 ,1
2. B) 1, 2, 1, 4
3. C) 2, 4, 2, 8
4. D) 1, 4, 1, 4
5. E) 2, 4, 2, 4

Answer: B

Objective: 7.1

Global Outcomes: GO2

5) What coefficient is placed in front of O2 to complete the balancing of the following equation?

C5H8 + ? O2 → 5CO2 + 4H2O

1. A) 1
2. B) 3
3. C) 5
4. D) 7
5. E) 9

Answer: D

Objective: 7.1

Global Outcomes: GO2

6) What is the coefficient of hydrogen, H2, when the following equation is balanced?

Al + H2SO4 → Al2(SO4)3 + ? H2

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

Answer: C

Objective: 7.1

Global Outcomes: GO2

7) In this reaction, what is the coefficient for calcium oxide?

CaO(s) + CO2(g) → CaCO3(s)

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

Answer: A

Objective: 7.1

Global Outcomes: GO2

8) In the following reaction, when the equation is correctly balanced, what is the correct coefficient for sodium chloride?

Pb(NO3)2(aq) + NaCl(aq) → PbCl2(s) + NaNO3(aq)

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

Answer: B

Objective: 7.1

Global Outcomes: GO2

9) In the following reaction, when the equation is correctly balanced, what is the correct coefficient for H2?

Fe(s) + HCl(aq) → FeCl3(aq) + H2(g)

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

Answer: C

Objective: 7.1

Global Outcomes: GO2

10) In the following reaction, when the equation is correctly balanced, what is the correct coefficient for aluminum chloride?

Al(s) + Cl2(g) → AlCl3(s)

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

Answer: B

Objective: 7.1

Global Outcomes: GO2

Pentane (C5H12) reacts with oxygen (O2) to form carbon dioxide (CO2) and water (H2O) according to the following reaction. Answer the question(s) that follow about this reaction.

C5H12 + ? O2 → ? CO2 + ? H2O

11) What is the coefficient for oxygen in the balanced equation?

1. A) 2
2. B) 4
3. C) 5
4. D) 6
5. E) 8

Answer: E

Objective: 7.1

Global Outcomes: GO2

12) What is the coefficient for carbon dioxide in the balanced equation?

1. A) 2
2. B) 4
3. C) 5
4. D) 6
5. E) 8

Answer: C

Objective: 7.1

Global Outcomes: GO2

13) What is the coefficient for water in the balanced equation?

1. A) 2
2. B) 4
3. C) 5
4. D) 6
5. E) 8

Answer: D

Objective: 7.1

Global Outcomes: GO2

14) In a ________ reaction, two or more elements or compounds form one product.

1. A) decomposition
2. B) single replacement
3. C) dehydration
4. D) double replacement
5. E) combination

Answer: E

Objective: 7.2

Global Outcomes: GO2

15) The following reaction takes place when an electric current is passed through water. It is an example of a ________ reaction.

2H2O → 2H2 + O2

1. A) combination
2. B) single replacement
3. C) dehydration
4. D) decomposition
5. E) double replacement

Answer: D

Objective: 7.2

Global Outcomes: GO2

16) What is the classification for this reaction?

SO3 (g) + H2O (l) → H2SO4(l)

1. A) decomposition
2. B) combination
3. C) replacement
4. D) double replacement
5. E) oxidation reduction

Answer: B

Objective: 7.2

Global Outcomes: GO2

17) The reaction of carbon with oxygen to produce carbon monoxide is an example of which class of reaction?

2C(s) + O2(g) → 2CO(g)

1. A) single replacement
2. B) double replacement
3. C) combination
4. D) catalytic
5. E) endothermic

Answer: C

Objective: 7.2

Global Outcomes: GO2

18) What is the classification for this unbalanced reaction?

Fe + HCl → FeCl3 + H2

1. A) dehydration
2. B) combination
3. C) decomposition
4. D) single replacement
5. E) double replacement

Answer: D

Objective: 7.2

Global Outcomes: GO2

19) The reaction of methane with oxygen to produce carbon dioxide and water is an example of which class of reaction?

CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)

1. A) single replacement
2. B) double replacement
3. C) combination
4. D) oxidation
5. E) endothermic

Answer: D

Objective: 7.2

Global Outcomes: GO2

20) Which of the following is an oxidation-reduction reaction?

1. A) CaCl2+ Na2SO4→ CaSO4 + 2NaCl
2. B) KOH + HNO3→ H2O + KNO3
3. C) N2+ O2→ 2NO
4. D) AgNO3+ NaCl → AgCl + NaNO3
5. E) Al2(SO4)3 + 6KOH → 2Al(OH)3+ 3K2SO4

Answer: C

Objective: 7.3

Global Outcomes: GO2

21) What is oxidized and what is reduced in the following reaction?

2Al(s) + 3Br2(g) → 2AlBr3(s)

1. A) Al is oxidized and Br2is reduced.
2. B) AlBr3is reduced and Br2is oxidized.
3. C) Al is reduced and Br2
4. D) AlBr3is reduced and Al is oxidized.
5. E) AlBr3is oxidized and Al is reduced.

Answer: A

Objective: 7.3

Global Outcomes: GO2

22) Which of the following describes an oxidation reaction?

1. A) loss of electrons or loss of oxygen
2. B) loss of electrons or gain of oxygen
3. C) loss of electrons or gain of hydrogen
4. D) gain of electrons or gain of oxygen
5. E) gain of electrons or loss of H

Answer: B

Objective: 7.3

Global Outcomes: GO2

23) In an oxidation-reduction reaction, the substance oxidized always

1. A) takes on oxygen atoms.
2. B) shows a loss of electrons.
3. C) gives up hydrogen atoms.
4. D) shows a gain of electrons.
5. E) becomes a charged species.

Answer: B

Objective: 7.3

Global Outcomes: GO2

24) In this reaction, what is the substance oxidized?

Zn(s) + 2 HCl(aq) → ZnCl2(aq) + H2(g)

1. A) chlorine
2. B) zinc chloride
3. C) hydrogen
4. D) zinc
5. E) oxygen

Answer: D

Objective: 7.3

Global Outcomes: GO2

25) In an oxidation-reduction reaction, the substance reduced always

1. A) takes on oxygen atoms.
2. B) shows a loss of electrons.
3. C) gives up hydrogen atoms.
4. D) shows a gain of electrons.
5. E) becomes a charged species.

Answer: D

Objective: 7.3

Global Outcomes: GO2

26) How many moles of iron are present in 3.15 × 1024 atoms of iron?

1. A) 5.23 moles
2. B) 1.90 moles
3. C) 292 moles
4. D) 0.523 moles
5. E) 1.90 × 1048moles

Answer: A

Objective: 7.4

Global Outcomes: GO4

27) How many atoms of neon are present in 1.30 moles of neon?

1. A) 3.15 × 1023atoms
2. B) 4.63 × 1023atoms
3. C) 7.83 × 1023atoms
4. D) 6.02 × 1023atoms
5. E) 7.83 × 1024atoms

Answer: C

Objective: 7.4

Global Outcomes: GO4

28) One mole of particles of any substance contains how many particles?

1. A) 106
2. B) 3 × 10-10
3. C) 3 × 1010
4. D) 6.02 × 1023
5. E) 6.02 × 10-23

Answer: D

Objective: 7.4

Global Outcomes: GO4

29) Avogadro’s number is the number of

1. A) particles in 1 mole of a substance.
2. B) amu in 1 mole of a substance.
3. C) grams in 1 mole of a substance.
4. D) moles in 6.02 × 1023grams of an element.
5. E) moles in 6.02 × 1023amu of an element.

Answer: A

Objective: 7.4

Global Outcomes: GO4

30) How many molecules of water, H2O, are present in 75.0 g of H2O?

1. A) 75.0 molecules
2. B) 4.17 molecules
3. C) 7.53 × 1024molecules
4. D) 2.51 × 1024molecules
5. E) 5.02 × 1024molecules

Answer: D

Objective: 7.5

Global Outcomes: GO4

31) How many hydrogen atoms are present in 75.0 g of H2O?

1. A) 75.0 atoms
2. B) 4.17 atoms
3. C) 7.53 × 1024atoms
4. D) 2.51 × 1024atoms
5. E) 5.02 × 1024atoms

Answer: E

Objective: 7.5

Global Outcomes: GO4

32) The molar mass of potassium is

1. A) 19 g.
2. B) 31.0 g.
3. C) 6.02 × 1023
4. D) 39.1 g.
5. E) 15g.

Answer: D

Objective: 7.5

Global Outcomes: GO4

33) One mole of helium gas has a mass of

1. A) 1.00 g.
2. B) 2.00 g.
3. C) 3.00 g.
4. D) 4.00 g.
5. E) 8.00 g.

Answer: D

Objective: 7.5

Global Outcomes: GO4

34) How many moles of water, H2O, are present in 75.0 g of H2O?

1. A) 4.41 moles
2. B) 4.16 moles
3. C) 75.0 moles
4. D) 7.50 moles
5. E) 1.35 × 103moles

Answer: B

Objective: 7.5

Global Outcomes: GO4

35) 0.100 mole of lithium has a mass of

1. A) 3.00 g.
2. B) 0.300 g.
3. C) 6.94 g.
4. D) 0.694 g.
5. E) 0.700 g.

Answer: D

Objective: 7.5

Global Outcomes: GO4

36) Calculate the molar mass of potassium chloride, KCl.

1. A) 74.6 g
2. B) 54.5 g
3. C) 6.74 g
4. D) 67.4 g
5. E) 19.0 g

Answer: A

Objective: 7.5

Global Outcomes: GO4

37) What is the molar mass of copper(II) sulfate, CuSO4?

1. A) 16.0 g
2. B) 63.6 g
3. C) 111.6 g
4. D) 159.6 g
5. E) 319.2 g

Answer: D

Objective: 7.5

Global Outcomes: GO4

38) Calculate the molar mass of magnesium chloride, MgCl2.

1. A) 24.3 g
2. B) 95.2 g
3. C) 125.9 g
4. D) 59.8 g
5. E) 70.0 g

Answer: B

Objective: 7.5

Global Outcomes: GO4

39) What is the molar mass of sodium phosphate, Na3PO4?

1. A) 119 g
2. B) 308 g
3. C) 164 g
4. D) 226 g
5. E) 354 g

Answer: C

Objective: 7.5

Global Outcomes: GO4

40) How many moles of carbon atoms are there in 0.500 mole of C2H6?

1. A) 0.500 moles
2. B) 1.00 moles
3. C) 3.00 moles
4. D) 6.02 × 1023moles
5. E) 4.00 moles

Answer: B

Objective: 7.5

Global Outcomes: GO4

41) What is the molar mass of sucrose (C12H22O11)?

1. A) 29.0 g
2. B) 50.2 g
3. C) 210 g
4. D) 342 g
5. E) 182 g

Answer: D

Objective: 7.5

Global Outcomes: GO4

42) One mole of neon atoms has a mass of

1. A) 6.02 × 1023
2. B) 14.0 g.
3. C) 10.0 g.
4. D) 20.2 g.
5. E) 30.2 g.

Answer: D

Objective: 7.5

Global Outcomes: GO4

43) The molar mass of C3H8O2 is

1. A) 76.0 g.
2. B) 60.0 g.
3. C) 29.0 g.
4. D) 69.0 g.
5. E) 52.0 g.

Answer: A

Objective: 7.5

Global Outcomes: GO4

44) The molar mass of calcium hydroxide, Ca(OH)2, is

1. A) 58.1 g.
2. B) 57.1 g.
3. C) 74.1 g.
4. D) 114.2 g.
5. E) 38.0 g.

Answer: C

Objective: 7.5

Global Outcomes: GO4

45) What is the molar mass of Mg3(PO4)2, a substance formerly used in medicine as an antacid?

1. A) 71.3 g
2. B) 118 g
3. C) 150. g
4. D) 214 g
5. E) 263 g

Answer: E

Objective: 7.5

Global Outcomes: GO4

46) 4.00 moles of sodium have a mass of

1. A) 4.60 g.
2. B) 11.0 g.
3. C) 23.0 g.
4. D) 44.0 g.
5. E) 92.0 g.

Answer: E

Objective: 7.5

Global Outcomes: GO4

47) How many moles of K2SO4 are in 15.0 g of K2SO4?

1. A) 0.172 moles
2. B) 2.61 × 103moles
3. C) 0.111 moles
4. D) 0.0861 moles
5. E) 0.119 moles

Answer: D

Objective: 7.5

Global Outcomes: GO4

48) 3.00 moles of NO2 have a mass of

1. A) 138 g.
2. B) 46.0 g.
3. C) 30.0 g.
4. D) 90.0 g.
5. E) 45.0 g.

Answer: A

Objective: 7.5

Global Outcomes: GO4

49) 1.25 moles of PbO2 have a mass of

1. A) 191 g.
2. B) 279 g.
3. C) 178 g.
4. D) 239 g.
5. E) 299 g.

Answer: E

Objective: 7.5

Global Outcomes: GO4

50) How many grams of Fe2O3 are there in 0.500 mole of Fe2O3?

1. A) 79.9 g
2. B) 35.9 g
3. C) 63.8 g
4. D) 51.9 g
5. E) 160. g

Answer: A

Objective: 7.5

Global Outcomes: GO4

51) How many grams of glucose (C6H12O6) are in 3.55 moles of glucose?

1. A) 180. g
2. B) 639 g
3. C) 103 g
4. D) 426 g
5. E) 50.7 g

Answer: B

Objective: 7.5

Global Outcomes: GO4

52) Given the following equation, what is the correct form of the conversion factor needed to convert the number of moles of O2 to the number of moles of Fe2O3 produced?

4Fe(s) + 3O2 (g) → 2Fe2O3(s)

A)

1. B)
2. C)
3. D)
4. E)

Answer: E

Objective: 7.6

Global Outcomes: GO4

For the question(s) that follow, consider the following equation.

2Mg + O2 → 2MgO

53) The number of moles of oxygen gas needed to react with 4.0 moles of Mg is

1. A) 1.0 mole.
2. B) 2.0 moles.
3. C) 3.0 moles.
4. D) 4.0 moles.
5. E) 6.0 moles.

Answer: B

Objective: 7.6

Global Outcomes: GO4

54) The number of moles of MgO produced when 0.20 mole of O2 reacts completely is

1. A) 0.10 mole.
2. B) 0.20 mole.
3. C) 0.40 mole.
4. D) 0.60 mole.
5. E) 0.80 mole.

Answer: C

Objective: 7.6

Global Outcomes: GO4

55) How many moles of magnesium are needed to react with 0.50 mole of O2?

1. A) 0.50 mole
2. B) 1.0 moles
3. C) 2.0 moles
4. D) 3.0 moles
5. E) 4.0 moles

Answer: B

Objective: 7.6

Global Outcomes: GO4

56) When 4 moles of aluminum are allowed to react with an excess of chlorine gas, Cl2, how many moles of aluminum chloride are produced?

1. A) 1 mole
2. B) 2 moles
3. C) 3 moles
4. D) 4 moles
5. E) 5 moles

Answer: D

Objective: 7.6

Global Outcomes: GO4

57) In the reaction of nitrogen gas, N2, with hydrogen gas, H2, to form ammonia gas, NH3 , how many moles of hydrogen are needed to react with two moles of nitrogen?

1. A) 2 moles
2. B) 4 moles
3. C) 6 moles
4. D) 8 moles
5. E) 10 moles

Answer: C

Objective: 7.6

Global Outcomes: GO4

For the question(s) that follow, consider the following balanced equation.

Mg3N2(s) + 6H2O(l) → 3Mg (OH)2(s) + 2NH3(g)

58) What is the correct form of the conversion factor needed to convert the number of moles of H2O to the number of moles of NH3 produced?

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

Answer: A

Objective: 7.6

Global Outcomes: GO4

59) When 2 moles of Mg3N2 are allowed to react, how many moles of H2O also react?

1. A) 1 mole
2. B) 4 moles
3. C) 6 moles
4. D) 8 moles
5. E) 12 moles

Answer: E

Objective: 7.6

Global Outcomes: GO4

For the question(s) that follow, consider the following equation.

2Mg + O2 → 2MgO

60) How many grams of MgO are produced when 40.0 grams of O2 react completely with Mg?

1. A) 30.4 g
2. B) 50.4 g
3. C) 60.8 g
4. D) 101 g
5. E) 201 g

Answer: D

Objective: 7.7

Global Outcomes: GO4

For the question(s) that follow, consider the following balanced equation.

Mg3N2(s) + 6H2O(l) → 3Mg (OH)2(s) + 2NH3(g)

61) How many grams of H2O are needed to produce 150 g of Mg(OH)2?

1. A) 46 g
2. B) 18 g
3. C) 130 g
4. D) 93 g
5. E) 23 g

Answer: D

Objective: 7.7

Global Outcomes: GO4

62) When 36.0 g of H2O react, how many grams of NH3 are produced?

1. A) 34.0 g
2. B) 10.0 g
3. C) 5.67 g
4. D) 11.3 g
5. E) 102 g

Answer: D

Objective: 7.7

Global Outcomes: GO4

63) How many grams of hydrogen are needed to produce 1.80 g of water according to this equation?

2H2 + O2 → 2H2O

1. A) 0.100 g
2. B) 0.180 g
3. C) 0.200 g
4. D) 2.00 g
5. E) 4.00 g

Answer: C

Objective: 7.7

Global Outcomes: GO4

64) In the reaction of silver nitrate with sodium chloride, how many grams of silver chloride will be produced from 100. g of silver nitrate when it is mixed with an excess of sodium chloride? The equation for the reaction is below.

AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq)

1. A) 107.9 g
2. B) 169.9 g
3. C) 84.4 g
4. D) 0.589 g
5. E) 58.9 g

Answer: C

Objective: 7.7

Global Outcomes: GO4

65) Find the mass of AlCl3 that is produced when 25.0 grams of Al2O3 react with excess HCl according to the following equation.

Al2O3(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2O(l)

1. A) 155 g
2. B) 72.9 g
3. C) 65.4 g
4. D) 32.6 g
5. E) 16.3 g

Answer: C

Objective: 7.7

Global Outcomes: GO4

66) How many grams of NO are required to produce 145 g of N2 in the following reaction?

4NH3(g) + 6NO(g) → 5N2(g) + 6H2O(l)

1. A) 186 g
2. B) 155 g
3. C) 125 g
4. D) 129 g
5. E) 145 g

Answer: A

Objective: 7.7

Global Outcomes: GO4

67) How many grams of N2 are produced from 100. g of NH3 in the following reaction?

4NH3(g) + 6NO(g) → 5N2(g) + 6H2O(l)

1. A) 165 g
2. B) 132 g
3. C) 125 g
4. D) 206 g
5. E) 7.35 g

Answer: D

Objective: 7.7

Global Outcomes: GO4

68) How many grams of CO2 are produced from 125 g of O2 and excess CH4?

CH4 + 2O2 → CO2 + 2H2O

1. A) 125 g of CO2
2. B) 62.5 g of CO2
3. C) 172 g of CO2
4. D) 85.9 g of CO2
5. E) 250. g of CO2

Answer: D

Objective: 7.7

Global Outcomes: GO4

69) When 3.05 moles of CH4 are mixed with 5.03 moles of O2 the limiting reactant is

CH4 + 2O2 → CO2 + 2H2O

1. A) CH4.
2. B) O2.
3. C) CO2.
4. D) H2

Answer: B

Objective: 7.8

Global Outcomes: GO4

70) When 85.0 g of CH4 are mixed with 160. g of O2 the limiting reactant is

CH4 + 2O2 → CO2 + 2H2O

1. A) CH4.
2. B) O2.
3. C) CO2.
4. D) H2

Answer: B

Objective: 7.8

Global Outcomes: GO4

71) When 10.0 g of NH3 reacts, the actual yield of N2 is 8.50 g. What is the percent yield?

4NH3(g) + 6NO(g) → 5N2(g) + 6H2O(l)

1. A) 85.0%
2. B) 51.5%
3. C) 20.6%
4. D) 41.3%
5. E) 8.5%

Answer: D

Objective: 7.8

Global Outcomes: GO7

72) When 85.0 g of CH4 are mixed with 160. g of O2 what is the maximum amount of CO2 that can be produced?

CH4 + 2O2 → CO2 + 2H2O

1. A) 2.50 moles
2. B) 5.00 moles
3. C) 5.31 moles
4. D) 7.81 moles

Answer: A

Objective: 7.8

Global Outcomes: GO4

73) When 60.0 g of CH4 reacts with excess O2, the actual yield of CO2 is 112 g. What is the percent yield?

CH4 + 2O2 → CO2 + 2H2O

1. A) 53.6 %
2. B) 187 %
3. C) 67.9 %
4. D) 46.4 %

Answer: C

Objective: 7.8

Global Outcomes: GO4

74) Find the mass of AlCl3 that is produced when 10.0 grams of Al2O3 react with 10.0 g of HCl according to the following equation.

Al2O3(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2O(aq)

1. A) 16.2 g
2. B) 20.0 g
3. C) 12.2 g
4. D) 10.0 g
5. E) 6.10 g

Answer: C

Objective: 7.8

Global Outcomes: GO4

75) What type of reaction is: CH4 + 2O2 → CO2 + 2H2O + 218 kcal?

1. A) an endothermic reaction
2. B) an exothermic reaction
3. C) a single replacement reaction
4. D) a combination reaction
5. E) a decomposition reaction

Answer: B

Objective: 7.9

Global Outcomes: GO2

76) How many kcal are produced when 32.0 g of CH4 react?

CH4 + 2O2 → CO2 + 2H2O + 218 kcal

1. A) 218 kcal
2. B) 109 kcal
3. C) 436 kcal
4. D) 6.81 kcal
5. E) 698 kcal

Answer: C

Objective: 7.9

Global Outcomes: GO4

77) For the reaction: 2H2O(l) + 137 kcal → 2H2 (g) + O2 (g), how many kcal are needed to form 2.00 moles O2 (g)?

1. A) 68.5 kcal
2. B) 137 kcal
3. C) 274 kcal
4. D) 190. kcal
5. E) 548 kcal

Answer: C

Objective: 7.9

Global Outcomes: GO4

78) For the reaction: 2H2O(l) + 137 kcal → 2H2 (g) + O2 (g), how many kcal are needed to react 50.0 g H2O(l)?

1. A) 380. kcal
2. B) 137 kcal
3. C) 274 kcal
4. D) 190. kcal
5. E) 760. kcal

Answer: D

Objective: 7.9

Global Outcomes: GO4

79) If the reaction shown below is exothermic, the energy level of the reactants is

H2 + O2 → 2H2O

1. A) lower than that of the products.
2. B) higher than that of the products.
3. C) the same as that of the products.
4. D) possibly lower, possibly higher than that of the products.
5. E) higher than the activation energy of the reaction.

Answer: B

Objective: 7.9

Global Outcomes: GO2

80) In an endothermic reaction

1. A) heat flows out of the system.
2. B) energy is absorbed by the system.
3. C) the temperature of the system increases.
4. D) the products have less energy that the reactants.
5. E) the products have the same energy that the reactants.

Answer: B

Objective: 7.9

Global Outcomes: GO2

81) Any reaction that absorbs 150 kcal of energy can be classified as

1. A) endothermic.
2. B) exothermic.
3. C) activated.
4. D) reduction.
5. E) oxidation.

Answer: A

Objective: 7.9

Global Outcomes: GO2

82) The ________ is the energy difference between reactants and products in a chemical reaction.

1. A) transition energy
2. B) activation energy
3. C) product energy
4. D) overall energy
5. E) heat of reaction

Answer: E

Objective: 7.9

Global Outcomes: GO2

83) The ________ is the minimum energy needed for a chemical reaction to begin.

1. A) reaction energy
2. B) activation energy
3. C) energy of reactants
4. D) energy of products
5. E) heat of reaction

Answer: B

Objective: 7.9

Global Outcomes: GO2

84) A reaction that releases energy as it occurs is classified as a(n)

1. A) endothermic reaction.
2. B) exothermic reaction.
3. C) oxidation-reduction reaction.
4. D) catalyzed reaction.
5. E) decomposition reaction.

Answer: B

Objective: 7.9

Global Outcomes: GO2

7.2 Bimodal Questions

1) In this reaction, what is the correct coefficient for hydrogen gas?

? H2 + ? O2 → ? H2O

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

Answer: B

Objective: 7.1

Global Outcomes: GO4

Barium chloride and sodium sulfate react according to the following equation.

BaCl2 + Na2SO4 → BaSO4 + 2NaCl

Answer the question(s) that follow about this reaction.

2) How many moles of barium sulfate are produced from 0.100 mole of barium chloride?

1. A) 0.0100 mole
2. B) 0.100 mole
3. C) 0.200 mole
4. D) 1.00 mole
5. E) 2.00 moles

Answer: B

Objective: 7.6

Global Outcomes: GO4

3) How many grams of barium sulfate can be produced from 20.8 g of barium chloride?

1. A) 1.37 g
2. B) 2.33 g
3. C) 23.3 g
4. D) 137 g
5. E) 233 g

Answer: C

Objective: 7.7

Global Outcomes: GO4

4) How many grams of barium chloride are needed to make 100. grams of barium sulfate?

1. A) 44.9 g
2. B) 89.2 g
3. C) 208.3 g
4. D) 233.3 g
5. E) 46.6 g

Answer: B

Objective: 7.7

Global Outcomes: GO4

Answer the question(s) that follow about the following reaction.

2H2O2 → 2H2O + O2

5) How many moles of oxygen gas can 0.88 mole of hydrogen peroxide (H2O2) produce, if decomposition is complete?

1. A) 0.50 mole
2. B) 0.88 mole
3. C) 1.8 moles
4. D) 2.0 moles
5. E) 0.44 mole

Answer: E

Objective: 7.6

Global Outcomes: GO4

6) How many grams of water will 100. grams of hydrogen peroxide (H2O2) produce?

1. A) 3600 g
2. B) 360. g
3. C) 5.88 g
4. D) 52.9 g
5. E) 106 g

Answer: D

Objective: 7.7

Global Outcomes: GO4

7) How many grams of hydrogen peroxide (H2O2) are needed to produce 25.0 g of oxygen?

1. A) 106 g
2. B) 26.6 g
3. C) 5.88 g
4. D) 25.0 g
5. E) 53.1 g

Answer: E

Objective: 7.7

Global Outcomes: GO4

8) How many moles of hydrogen peroxide (H2O2) are needed to produce 5.0 moles of water?

1. A) 1.0 mole
2. B) 2.0 moles
3. C) 4.0 moles
4. D) 5.0 moles
5. E) 8.0 moles

Answer: D

Objective: 7.6

Global Outcomes: GO4

7.3 Short Answer Questions

1) What type of reaction is the following?

2KClO3 → 2KCl + 3O2

Answer: decomposition reaction

Objective: 7.2

Global Outcomes: GO2

2) What type of reaction is the following?

Zn + 2HCl → ZnCl2 + H2

Answer: single replacement reaction

Objective: 7.2

Global Outcomes: GO2

3) What type of reaction is the following?

2KClO3 → 2KCl + 3O2

Answer: decomposition reaction

Objective: 7.2

Global Outcomes: GO2

4) What type of reaction is the following?

Zn + 2HCl → ZnCl2 + H2

Answer: single replacement reaction

Objective: 7.2

Global Outcomes: GO2

5) The number of particles in 1 mole of hydrogen gas is ________.

Answer: 6.02 × 1023

Objective: 7.4

Global Outcomes: GO4

6) The molar mass of copper(II) nitrate, Cu(NO3)2 is ________.

Answer: 187.6 g

Objective: 7.5

Global Outcomes: GO4

7) What is the mass of 1 mole of argon gas?

Answer: 40.0 g

Objective: 7.5

Global Outcomes: GO4

8) What is the mass of 1 mole of helium gas?

Answer: 4.00 g

Objective: 7.5

Global Outcomes: GO4

9) Acetylene gas, C2H2, reacts with oxygen according to the following equation. If 1.00 mole of acetylene reacts completely with sufficient oxygen, how many moles of carbon dioxide are produced?

2C2H2 + 5O2 → 4CO2 + 2H2O

Answer: 2.00 moles of CO2

Objective: 7.6

Global Outcomes: GO4

7.4 True/False Questions

1) The following reaction is balanced.

KClO3 → KCl + O2

Answer: FALSE

Objective: 7.1

Global Outcomes: GO2

2) The following is a decomposition reaction.

2KClO3 → 2KCl + 3O2

Answer: TRUE

Objective: 7.2

Global Outcomes: GO2

3) Loss of electrons is an oxidation.

Answer: TRUE

Objective: 7.3

Global Outcomes: GO2

4) Avogadro’s number is the number of grams in a mole.

Answer: FALSE

Objective: 7.4

Global Outcomes: GO4

5) The molar mass of silver is 47 g.

Answer: FALSE

Objective: 7.5

Global Outcomes: GO4

6) The molar mass of magnesium is 24.3 g.

Answer: TRUE

Objective: 7.5

Global Outcomes: GO4

7) The mass of one mole of water is 18.0 g.

Answer: TRUE

Objective: 7.5

Global Outcomes: GO4

8) The molar mass of chlorine gas is 35.5 g.

Answer: FALSE

Objective: 7.5

Global Outcomes: GO4

9) The molar mass of copper(II) chloride is 134.5 g.

Answer: TRUE

Objective: 7.5

Global Outcomes: GO4

10) In the reaction of hydrogen gas with oxygen gas to produce water, 1 mole of oxygen gas can produce 2 moles of water, given sufficient hydrogen available.

Answer: TRUE

Objective: 7.6

Global Outcomes: GO4

11) In the reaction of hydrogen gas with oxygen gas to produce water, 16.0 g of oxygen gas can produce

9.00 g of water, given sufficient hydrogen available.

2H2 + O2 → 2H2O

Answer: FALSE

Objective: 7.7

Global Outcomes: GO4

12) The % yield is the ratio of the theoretical yield to the actual yield multiplied by 100.

Answer: FALSE

Objective: 7.9

Global Outcomes: GO2

13) In an exothermic reaction, heat is a product.

Answer: TRUE

Objective: 7.9

Global Outcomes: GO1

7.5 Matching Questions

Identify the energy associated with each of the labeled parts of the following diagram.

1. A) energy of reactants
2. B) heat of reaction
3. C) activation energy
4. D) energy of products

1) Region A

Objective: 7.9

Global Outcomes: GO3

2) Region B

Objective: 7.9

Global Outcomes: GO3

3) Region C

Objective: 7.9

Global Outcomes: GO3

4) Region D

Objective: 7.9

Global Outcomes: GO3

Answers: 1) A 2) C 3) B 4) D

Identify the letter of the diagram corresponding to the given type of reaction.

A

B

1. A) Diagram A
2. B) Diagram B

5) endothermic reaction

Objective: 7.9

Global Outcomes: GO3

6) exothermic reaction

Objective: 7.9

Global Outcomes: GO3

Answers: 5) B 6) A