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🧪 Chemistry  ·  Hydrogen  ·  NEET & JEE

The anomalous properties of water compared to H<sub>2</sub>S, H<sub>2</sub>Se, H<sub>2</sub>Te are due to:

Answer: Hydrogen bonding in water raises its boiling point far above the trend expected from molecular weight.

  • A Hydrogen bonding in water raises its boiling point far above the trend expected from molecular weight
  • B Water generally having a higher molecular weight than the other hydrides overall in most cases under typical conditions
  • C Water possessing significant ionic character in its O-H bonds according to standard textbooks in general practice
  • D Oxygen being a physically larger atom than sulfur, selenium, or tellurium as frequently described

Correct answer: A. Hydrogen bonding in water raises its boiling point far above the trend expected from molecular weight

Explanation: Extrapolating the boiling points of H<sub>2</sub>S (-61°C), H<sub>2</sub>Se (-41°C), H<sub>2</sub>Te (-2°C) would predict H<sub>2</sub>O to boil at about -80°C. Hydrogen bonding raises it to 100°C.

Hydrogen Bonding Network in WaterOHHOHHOHHOHHDashed green lines = hydrogen bonds (weaker than O-H covalent bonds)

Each water molecule's O-H bonds (covalent, solid) can hydrogen-bond (dashed) to neighbouring molecules, forming an extended network responsible for water's unusually high boiling point and density anomaly.

Concept context

The simplest and most abundant element in the universe. Study its unique position in the periodic table, isotopes (protium, deuterium, tritium), properties of water and hydrogen peroxide, and industrial uses.

Read the full Hydrogen notes →