CHEM 115 FINAL EXAM 2026/2027 QUESTIONS AND
SOLUTIONS RATED A+
✔✔Which of the following statements about Lewis structures is FALSE?
A) An octet is when an atom has 8 valence electrons.
B) A duet is a stable electron configuration for helium.
C) A covalent bond occurs when electrons are shared.
D) An ionic bond occurs when electrons are transferred.
E) All of the above statements are true - ✔✔C
✔✔What is the molecular geometry if you have 4 single bonds around the central atom?
A) linear
B) tetrahedral
C) trigonal pyramidal
D) bent
E) not enough information - ✔✔E
✔✔Which compound listed below will dissolve in NH3?
A) CO2
B) H2S
C) O2
D) all of the compounds
E) none of the compounds - ✔✔B
✔✔. The electronegativity value for Mg is 1.2 and the value for O is 3.5. Based on these
values, what
type of bond is expected for a compound formed between Mg and O?
A) Polar covalent
B) Ionic
C) Pure covalent
D) not enough information
E) none of the above - ✔✔B
✔✔The central atom in the chlorate anion, ClO3
- is surrounded by
A) two bonding and two unshared pairs of electrons.
B) two double bonds and no unshared pairs of electrons.
C) one bonding and three unshared pairs of electrons.
D) three bonding and one unshared pair of electrons.
E) none of the above. - ✔✔B
✔✔The electronegativity value for N is 3.0 and that for O is 3.5. Based on these values,
which of the
following statements is TRUE about the compound NO?
A) NO is a pure covalent compound.
, B) NO is an ionic compound.
C) NO is a polar covalent compound.
D) There is not enough enough information to determine the nature of NO.
E) None of the above statements is true. - ✔✔D
✔✔Which Lewis structure below correctly represents the compound formed between
magnesium and
sulfur?
A) [:
..
S
··
:]⁻ Mg⁺2 [:
..
S
··
:]⁻
B) Mg⁺ [:
..
S
··
:]⁻2 Mg⁺
C) Mg⁺ [:
..
S
··
:]⁻
D) Mg⁺2 [:
..
S
··
:]⁻2
E) none of the above - ✔✔D
✔✔. Which molecule listed below has a polar covalent bond?
A) H2O
B) NaCl
C) H2
D) all of the compounds
E) none of the compounds - ✔✔A
✔✔Which of the following statements about the water molecule is TRUE?
A) A water molecule has two dipole moments and they cancel each other.
B) A water molecule is symmetrical and therefore is nonpolar.
SOLUTIONS RATED A+
✔✔Which of the following statements about Lewis structures is FALSE?
A) An octet is when an atom has 8 valence electrons.
B) A duet is a stable electron configuration for helium.
C) A covalent bond occurs when electrons are shared.
D) An ionic bond occurs when electrons are transferred.
E) All of the above statements are true - ✔✔C
✔✔What is the molecular geometry if you have 4 single bonds around the central atom?
A) linear
B) tetrahedral
C) trigonal pyramidal
D) bent
E) not enough information - ✔✔E
✔✔Which compound listed below will dissolve in NH3?
A) CO2
B) H2S
C) O2
D) all of the compounds
E) none of the compounds - ✔✔B
✔✔. The electronegativity value for Mg is 1.2 and the value for O is 3.5. Based on these
values, what
type of bond is expected for a compound formed between Mg and O?
A) Polar covalent
B) Ionic
C) Pure covalent
D) not enough information
E) none of the above - ✔✔B
✔✔The central atom in the chlorate anion, ClO3
- is surrounded by
A) two bonding and two unshared pairs of electrons.
B) two double bonds and no unshared pairs of electrons.
C) one bonding and three unshared pairs of electrons.
D) three bonding and one unshared pair of electrons.
E) none of the above. - ✔✔B
✔✔The electronegativity value for N is 3.0 and that for O is 3.5. Based on these values,
which of the
following statements is TRUE about the compound NO?
A) NO is a pure covalent compound.
, B) NO is an ionic compound.
C) NO is a polar covalent compound.
D) There is not enough enough information to determine the nature of NO.
E) None of the above statements is true. - ✔✔D
✔✔Which Lewis structure below correctly represents the compound formed between
magnesium and
sulfur?
A) [:
..
S
··
:]⁻ Mg⁺2 [:
..
S
··
:]⁻
B) Mg⁺ [:
..
S
··
:]⁻2 Mg⁺
C) Mg⁺ [:
..
S
··
:]⁻
D) Mg⁺2 [:
..
S
··
:]⁻2
E) none of the above - ✔✔D
✔✔. Which molecule listed below has a polar covalent bond?
A) H2O
B) NaCl
C) H2
D) all of the compounds
E) none of the compounds - ✔✔A
✔✔Which of the following statements about the water molecule is TRUE?
A) A water molecule has two dipole moments and they cancel each other.
B) A water molecule is symmetrical and therefore is nonpolar.
