Is the molecule polar?

Answer Key - Grade 10 Science Worksheet

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

1. 1.

   Water's dipole moment is 1.857 D and HCl's is 1.093 D. How many times larger is water's, to 0.01, Ari?

   1.7 times

2. Read this first

   Measured dipole moments (NIST CCCBDB) (NIST CCCBDB)

   molecule	dipole moment (D)
   H₂O	1.857
   HF	1.827
   NH₃	1.476
   HCl	1.093
   CO	0.112
   CO₂	0
   CH₄	0

3. 2.

   Using the table, which two molecules are nonpolar, Jun?

   • H₂O and HF
   • CO₂ and CH₄
   • NH₃ and CO
4. 3.

   Using the table, which molecule is most polar, Kira?

   • CO
   • CH₄
   • H₂O
5. 4.

   Using the table, how polar is CO, Luz?

   • Nonpolar
   • Slightly polar
   • More polar than water
6. 5.

   CO₂ and H₂O both have polar bonds. Why is only H₂O polar, Milo?

   • Water is heavier
   • Water is bent; CO₂ is linear
   • Water's bonds are polar; CO₂'s aren't
7. 6.

   BF₃ has polar B–F bonds in a flat triangle. Is it polar, Noah?

   • Yes: its bonds are polar, so it is
   • No: the three dipoles cancel
   • Yes: fluorine is heavy
8. 7.

   Why is NH₃ polar while BF₃ isn't, Pia?

   • NH₃'s pyramid doesn't cancel
   • NH₃ has more atoms than BF₃ does
   • BF₃ has no bonds
9. 8.

   In a described demo, a thin water stream bends toward a charged comb. Why, Ren?

   • Water is magnetic and attracted
   • Water molecules are polar
   • The comb is wet
10. 9.

    Why do oil and water separate into layers, Tala?

    • Both are polar
    • Oil is heavier than water
    • Water is polar; oil is nonpolar
11. 10.

    Why does sugar dissolve well in water, Zee?

    • Sugar is a metal
    • Water is nonpolar
    • Both are polar