Multiple Choice
Which of the following molecules contains polar bonds but is overall non-polar?
1
views
13. Liquids, Solids & Intermolecular Forces
Molecular Polarity
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Which of the following best describes the molecular polarity of BeF_2?
A
BeF_2 is nonpolar due to its bent shape.
B
BeF_2 is a polar molecule.
C
BeF_2 is ionic and therefore polar.
D
BeF_2 is a nonpolar molecule.
Verified step by step guidance1
Identify the molecular geometry of BeF_2 by considering the number of bonding pairs and lone pairs around the central atom (Be). Since Be forms two bonds with F atoms and has no lone pairs, the shape is linear.
Recall that in a linear molecule like BeF_2, the bond angle between the two Be-F bonds is 180 degrees, meaning the bonds are directly opposite each other.
Determine the polarity of each Be-F bond. Because fluorine is more electronegative than beryllium, each Be-F bond is polar with a dipole moment pointing from Be to F.
Analyze the vector sum of the bond dipoles. In a linear molecule, the two bond dipoles are equal in magnitude but opposite in direction, so they cancel each other out.
Conclude that since the bond dipoles cancel, the overall molecule has no net dipole moment, making BeF_2 a nonpolar molecule despite having polar bonds.
Related Videos
Related Practice
Molecular Polarity practice set
Problem sets built by lead tutorsExpert video explanations