Test Unit 6 Chemical Structure

CO₂ has polar C=O bonds, but is a NON POLAR molecule. Explain why.

• CO₂ has no symmetrical shape to it, making it nonpolar.

• Bond polarity (or dipole moment) between C and O atoms cancel due to symmetry.

• Bond polarity (or dipole moment) between C and O atoms do not cancel and is stronger to the left side of the molecule.

• Electronegativity of C and O atoms are the same therefore makes the molecule nonpolar.

Identify the molecule that could potentially take this molecular geometry (shape).

• BF₃
• CH₃

• H₃O⁺¹

• CO₂

Tags

NGSS.HS-PS1-3

Identify the TOTAL number of electrons participating in bonding for the molecule pictured.

• 8

• 6

• 2

• 3

The steric number is used to identify the molecular geometry of a molecule.

Identify the steric number for the molecule pictured (number of bonding + nonbonding sites).

• 5

• 4

• 3

• 2

Organize these options into the correct categories

Groups:

(a) Ionic Bond

,

(b) Polar Covalent Bond

,

(c) Non-polar Covalent Bond

• When one atom takes or gives electrons to another atom

• When electrons are shared unevenly

• Bond formed between two DIFFERENT nonmetals

• Formed by ions held together by electrostatic attraction

• Bond between diatomic elements (Br₂, Cl₂, N₂, O₂ )

• When electrons are shared evenly

• Bond formed between a metal and nonmetal atom

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Identify the intermolecular force that occurs between two POLAR molecules.

If needed, use the image provided.

• Ion-Dipole Force

• Dipole-Dipole Force

• Hydrogen bonding Force

• Dark Force

In general, substances with stronger intermolecular forces have ________ boiling points.

• Higher
• Lower
• Intermolecular Forces have no affect on boiling point.

Water, H₂O, is liquid at room temperature, while hydrogen sulfide, H₂S, is a gas at room temperature. Both have the same Lewis dot structure (tetrahedral, bent).

The difference in states of matter could be due to which of the following:

• H₂O has a dipole force while H₂S has no dipole force.

• H₂O has hydrogen bonding force, while H₂S has no dipole force.

• H₂O has dipole force, while H₂S also has a dipole force.

• H₂O has hydrogen bonding force, while H₂S has only dipole force.

Define: Dipole (Polar molecule)

(Use the image provided for help)

• A covalent molecule with partial positive and negative sides caused by differences in electronegativity of atoms.

• An ionic compound with positive and negative ions caused by differences in electronegativity of atoms.

• A covalent molecule with magnetic dipoles caused by differences in electronegativity of atoms.

• An ionic compound with magnetic dipoles caused by differences in electronegativity of atoms.

Tags

NGSS.HS-PS2-6

Explain how covalent bonds form.

• Complete transfer of valence electrons between atoms to form ions.

• Opposite slight charges attract each other between compounds.
• Scientists are still not sure how they form.
• Sharing of valence electrons between nonmetal atoms.