Question

question 7
1 pts
which of the following statements about the polarity of a molecule is false?
unequal sharing of bonding electron pairs is what leads to polar bonds within a molecule.
lone (unshared) pairs of electrons on the central atom play an important role in influencing polarity.
a perfectly linear molecule will always be a polar molecule.
polar molecules must have a net dipole moment.
question 8
1 pts
co₂ is a non - polar molecule with polar covalent bonds, which means
it could not possibly interact with infrared radiation.
carbon and oxygen must have exactly the same electronegativities.
it must have the proper symmetry for the individual polarities (dipoles) to cancel out.
it must remain near the equator to remain non - polar.

Explanation:

Question 7

• For the first option: Unequal sharing of bonding electrons (due to electronegativity differences) creates polar bonds, so this is true.
• Second option: Lone pairs on the central atom affect molecular geometry and thus polarity (e.g., in \( \text{H}_2\text{O} \), lone pairs make it bent and polar), so this is true.
• Third option: A linear molecule like \( \text{CO}_2 \) (linear, non - polar) or \( \text{HCl} \) (linear, polar). A perfectly linear molecule with symmetrically arranged polar bonds (like \( \text{CO}_2 \), \( \text{O}=\text{C}=\text{O} \)) will be non - polar because the bond dipoles cancel. So the statement "A perfectly linear molecule will always be a polar molecule" is false.
• Fourth option: By definition, polar molecules have a net dipole moment (vector sum of bond dipoles and lone pair effects), so this is true.

• First option: \( \text{CO}_2 \) can interact with infrared radiation (it's a greenhouse gas), so this is false.
• Second option: Carbon and oxygen have different electronegativities (oxygen is more electronegative), so the bonds are polar covalent. This statement is false.
• Third option: \( \text{CO}_2 \) is linear (\( \text{O}=\text{C}=\text{O} \)). The two \( \text{C}=\text{O} \) bond dipoles are equal in magnitude and opposite in direction, so they cancel out due to the molecule's symmetry. So this statement is true.
• Fourth option: The polarity of \( \text{CO}_2 \) has nothing to do with its location relative to the equator. This statement is false.

Answer:

C. A perfectly linear molecule will always be a polar molecule.

Question 8