Is the molecule polar?

Answer Key - Grade 10 Science Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

1. 1.

   A bent molecule has two bond dipoles of 1.51 D each at 104.48° (example values, like water). Using 2μ cos(θ ÷ 2), what is the net dipole, to 0.01 D, Ari?

   1.85 D
2. 2.

   A linear molecule has two bond dipoles of 0.8 D each at 180° (example values, like CO₂). Using 2μ cos(θ ÷ 2), what is the net dipole, Esme?

   0 D
3. 3.

   Is carbon monoxide, CO, polar, Jun?

   • Yes, slightly
   • No: it has no bonds
   • No: it is linear
4. 4.

   Is HCl polar, Kira?

   • No: it is an ion
   • Yes: its one bond is polar
   • No: it is linear
5. 5.

   Which of these must be nonpolar, Luz?

   • O₂, two identical atoms
   • H₂O
   • NH₃
6. 6.

   Noah says BF₃ must be polar because B–F bonds are polar. Agree or disagree?

   • Agree: fluorine is reactive
   • Disagree: the three cancel
   • Agree: polar bonds make it polar
7. 7.

   Pia says a linear molecule with two equal bond dipoles has a net dipole of 0. Agree or disagree?

   • Agree: cos 90° is 0
   • Disagree: lines are polar
   • Disagree: dipoles add up
8. 8.

   Which is more polar, HF or HCl, Ren?

   • HCl
   • They are equal
   • HF, at 1.827 D
9. 9.

   Which is more polar, water or ammonia, Tala?

   • Ammonia
   • Water
   • They are equal
10. 10.

    Why is HF more polar than HCl, Zee?

    • Chlorine is more electronegative
    • Fluorine is more electronegative
    • HF is bent