Polarity of Bond and Polarity of Molecule 24

Which molecule contains a nonpolar covalent bond?

• O=C=O

• C≡O

• Br—Br

• CCl₄

Answer explanation

The Br—Br bond is a nonpolar covalent bond because it involves two identical bromine atoms sharing electrons equally. In contrast, the other options involve polar or multiple bonds, which do not qualify as nonpolar.

Which bond is most polar?

• H—F

• H—Cl

• H—Br

• H—I

Answer explanation

The H—F bond is the most polar because fluorine is the most electronegative element, creating a significant difference in electronegativity between H and F. This results in a stronger dipole moment compared to the other bonds.

Which type of bond exists between an atom of carbon and an atom of fluorine?

• ionic

• metallic

• polar covalent

• nonpolar covalent

Answer explanation

The bond between carbon and fluorine is polar covalent due to the significant difference in electronegativity. Carbon is less electronegative than fluorine, causing an unequal sharing of electrons and creating a dipole.

Which substance contains nonpolar covalent bonds?

• H₂

• H₂O

• Ca(OH)₂

• CaO

Answer explanation

H₂ contains nonpolar covalent bonds because it consists of two hydrogen atoms sharing electrons equally. In contrast, H₂O, Ca(OH)₂, and CaO contain polar or ionic bonds, making H₂ the only option with nonpolar covalent bonds.

Which type of bond is formed between the carbon atom and the oxygen atom in CH₃OH?

• ionic

• electrovalent

• polar covalent

• nonpolar covalent

Answer explanation

In CH₃OH, the bond between carbon and oxygen is polar covalent due to the difference in electronegativity. Oxygen is more electronegative, causing a partial negative charge on oxygen and a partial positive charge on carbon.

Tags

NGSS.HS-PS1-3

Which electron-dot diagram represents a molecule that has a polar covalent bond?

• H—Cl

• Li⁺[Cl⁻]

• Cl—Cl

• K⁺[Cl⁻]

Answer explanation

The H—Cl bond is polar covalent because of the difference in electronegativity between hydrogen and chlorine, leading to an unequal sharing of electrons. The other options represent ionic or nonpolar bonds.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The bonds between hydrogen and oxygen in a water molecule are classified as

• polar covalent

• ionic

• nonpolar covalent

• metallic

Answer explanation

The bonds between hydrogen and oxygen in a water molecule are classified as polar covalent because oxygen is more electronegative than hydrogen, causing an unequal sharing of electrons and creating a dipole moment.

Which type of molecule is CF₄?

• polar, with a symmetrical distribution of charge

• polar, with an asymmetrical distribution of charge

• nonpolar, with a symmetrical distribution of charge

• nonpolar, with an asymmetrical distribution of charge

Answer explanation

CF₄ (carbon tetrafluoride) is a symmetrical molecule with four fluorine atoms evenly distributed around the central carbon atom. This symmetry leads to a nonpolar molecule, as the dipoles cancel out, resulting in a symmetrical charge distribution.

Which of the following compounds has the highest boiling point?

• H₂O

• H₂S

• H₂Se

• H₂Te

Answer explanation

H₂O has the highest boiling point due to strong hydrogen bonding between its molecules, which requires more energy to break compared to the weaker van der Waals forces in H₂S, H₂Se, and H₂Te.

Which of these formulas contains the most polar bond?

• H—Br

• H—Cl

• H—F

• H—I

Answer explanation

The H—F bond is the most polar because fluorine is the most electronegative element, creating a significant difference in electronegativity between hydrogen and fluorine compared to the other bonds.