Moderate

The boiling point of water is higher than other hydrides because water molecules can form:

Correct answer: A. 4 hydrogen bonds

  • A. 4 hydrogen bonds
  • B. 3 hydrogen bonds
  • C. 2 hydrogen bonds
  • D. 1 hydrogen bonds

Explanation

Intermolecular hydrogen bonding is responsible for the high boiling point of water (100 °C) compared to the other group 16 hydrides that have no hydrogen bonds. For example if we take comparison of fluorine and H20,Fluorine is more electronegative than Oxygen, so technically, HF should engage in more hydrogen bonding than water. But the situation is different. Each HF molecule possesses three lone pairs of fluorine and one hydrogen. HF molecules on average make two hydrogen bonds. Each H2O molecule possesses two lone pairs of oxygen. H2O molecules are thus able to form an average of four hydrogen bonds. Hence, water molecules take part in more hydrogen bonding than Hydrofluoric acid. Water molecules form a bulky molecule and it is very difficult to break its bonds. To break all its bonds, a large amount of the energy is required. Thus, H2O has a higher boiling point than HF. Thus h20 can form four hydrogen bonds.

Last updated

About Chemical Bonding

Chemical bonding explains molecular shape through VSEPR theory and distinguishes sigma bonds from pi bonds. Questions involve hybridization, bond angles, dipole moment and bond energy, including how electron-pair repulsion determines geometry and how bond polarity differs from the overall polarity of a molecule.

Practise Chemical Bonding

964 free Chemical Bonding MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Exams that ask Chemistry questions like this

Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

Related questions