AP Chemistry Midterm Exam Questions
With Correct Answers
Which of the following statements are true, concerning the Lewis dot structure
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for the molecule CIF3?
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A) It has and expanded octet
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B) It has a reduced octet
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C) This molecule contains a double or triple bond
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D) This molecule has no special features - CORRECT ANSWER✔✔-B) It has a
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reduced octet |
Which of these compounds is isoelectronic with CO2?
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A) NO2
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B) SiO2
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C) H2O
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D) SeO2 - CORRECT ANSWER✔✔-B) SiO2, Since C and Si are in the same family,
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their structures with oxygen will be isoelectronic
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Which of the following statements is true, concerning the Lewis dot structure for
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the molecule COF2?
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A) It has an expanded octet
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B) it has a reduced octet
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C) This molecule contains a double or triple bond
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,D) This molecule has no special features - CORRECT ANSWER✔✔-C) This molecule
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contains a double or triple bond
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Laughing gas, chemical know as nitrous oxide (N2O) is used to calm the nerves of
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dental patients around the world. This chemical has three possible resonance
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structures. The three structures are shown below. Use the formal charges to
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identify the most likely structure of N2O.
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| **N---N-O****** (0,+1,-1) ****N--N--O**** ******N-N---O** | | |
A) #1|
B) #2|
C)#3
D) These structures are equally likely - CORRECT ANSWER✔✔-A) #1 It has the
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most electronegative elelment, oxygen as the most negative charge.
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When copper is mixed with nitric acid, there is brown, noxious gas that forms,
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called nitrogen dioxide. The equation is shown below.
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Cu + 4HNO3 --> Cu(NO3)2 + 2H2O +2NO3
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A) NO2 contains an expanded octet, which makes it unstable.
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B) NO2 has an high positive formal charge on oxygen, which makes it
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unstable.
C) NO2 contains a lone pair on the central atom, which makes it unstable.
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D) NO2 is a free radical, which makes it unstable. Know the Lewis dot Structure -
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CORRECT ANSWER✔✔-D) NO2 is a free radical, which makes it unstable. Know
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the Lewis dot Structure
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Determine the molecular shape of SF4. | | | | |
, A) Tetrahedral
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B) Square Planar
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C) See-Saw
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D) Octahedral - CORRECT ANSWER✔✔-C) See-Saw
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Determine the bond angle around nitrogen in the structure shown below.
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A) 120 degrees
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B) <120 degrees
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C) 90 degrees
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D) none of these - CORRECT ANSWER✔✔-B) <120 degrees
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Order the following bonds in order of increasing polarity.
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H-F, F-F, Br-F, Cl-F
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A) F-F < H-F < Cl-F < Br-F
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B) F-F < Cl-F < Br-F < H-F
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C) H-F < Br-F < Cl-F < F-F
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D) H-F < F-F < Cl-F < Br-F - CORRECT ANSWER✔✔-B) F-F < Cl-F < Br-F < H-F
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Elements with the GREATEST difference in electronegativity are most polar
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Which statement is incorrect?
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A) Carbon is the negative end of the dipole in the C-O bond.
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B) Nitrogen is the negative end of the dipole in the N-H bond.
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C) Fluorine is the negative end of the dipole in the Cl-F bond.
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With Correct Answers
Which of the following statements are true, concerning the Lewis dot structure
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for the molecule CIF3?
| | |
A) It has and expanded octet
| | | | |
B) It has a reduced octet
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C) This molecule contains a double or triple bond
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D) This molecule has no special features - CORRECT ANSWER✔✔-B) It has a
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reduced octet |
Which of these compounds is isoelectronic with CO2?
| | | | | | |
A) NO2
|
B) SiO2
|
C) H2O
|
D) SeO2 - CORRECT ANSWER✔✔-B) SiO2, Since C and Si are in the same family,
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their structures with oxygen will be isoelectronic
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Which of the following statements is true, concerning the Lewis dot structure for
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the molecule COF2?
| |
A) It has an expanded octet
| | | | |
B) it has a reduced octet
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C) This molecule contains a double or triple bond
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,D) This molecule has no special features - CORRECT ANSWER✔✔-C) This molecule
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contains a double or triple bond
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Laughing gas, chemical know as nitrous oxide (N2O) is used to calm the nerves of
| | | | | | | | | | | | | | |
dental patients around the world. This chemical has three possible resonance
| | | | | | | | | | |
structures. The three structures are shown below. Use the formal charges to
| | | | | | | | | | | |
identify the most likely structure of N2O.
| | | | | |
| **N---N-O****** (0,+1,-1) ****N--N--O**** ******N-N---O** | | |
A) #1|
B) #2|
C)#3
D) These structures are equally likely - CORRECT ANSWER✔✔-A) #1 It has the
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most electronegative elelment, oxygen as the most negative charge.
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When copper is mixed with nitric acid, there is brown, noxious gas that forms,
| | | | | | | | | | | | | |
called nitrogen dioxide. The equation is shown below.
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Cu + 4HNO3 --> Cu(NO3)2 + 2H2O +2NO3
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A) NO2 contains an expanded octet, which makes it unstable.
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B) NO2 has an high positive formal charge on oxygen, which makes it
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unstable.
C) NO2 contains a lone pair on the central atom, which makes it unstable.
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D) NO2 is a free radical, which makes it unstable. Know the Lewis dot Structure -
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CORRECT ANSWER✔✔-D) NO2 is a free radical, which makes it unstable. Know
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the Lewis dot Structure
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Determine the molecular shape of SF4. | | | | |
, A) Tetrahedral
|
B) Square Planar
| |
C) See-Saw
|
D) Octahedral - CORRECT ANSWER✔✔-C) See-Saw
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Determine the bond angle around nitrogen in the structure shown below.
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A) 120 degrees
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B) <120 degrees
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C) 90 degrees
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D) none of these - CORRECT ANSWER✔✔-B) <120 degrees
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Order the following bonds in order of increasing polarity.
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H-F, F-F, Br-F, Cl-F
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A) F-F < H-F < Cl-F < Br-F
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B) F-F < Cl-F < Br-F < H-F
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C) H-F < Br-F < Cl-F < F-F
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D) H-F < F-F < Cl-F < Br-F - CORRECT ANSWER✔✔-B) F-F < Cl-F < Br-F < H-F
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Elements with the GREATEST difference in electronegativity are most polar
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Which statement is incorrect?
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A) Carbon is the negative end of the dipole in the C-O bond.
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B) Nitrogen is the negative end of the dipole in the N-H bond.
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C) Fluorine is the negative end of the dipole in the Cl-F bond.
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