Chemistry 9701 · AS & A Level · Chemical bonding

Chemical bonding — practice question

As the electronegativity of the atom bonded to hydrogen increases, the strength of hydrogen bonding also increases. Information on a range of hydrides is provided. Which statement together with its reason about these hydrides is correct?

  • AThe boiling point of $\text{PH}_3$ is much lower than the boiling point of $\text{H}_2\text{O}$ because $\text{PH}_3$ does not form hydrogen bonds or instantaneous dipole-induced dipole forces between its molecules.
  • BThe boiling point of $\text{HF}$ is higher than the boiling point of $\text{HCl}$ because the bond energy of H-F is greater than the bond energy of H-Cl.
  • CThe boiling point of $\text{H}_2\text{O}$ is higher than the boiling point of $\text{HF}$ because each hydrogen bond between $\text{H}_2\text{O}$ molecules is stronger than each hydrogen bond between $\text{HF}$ molecules.
  • DThe boiling points of $\text{PH}_3$ and $\text{HCl}$ are similar because the molecules of $\text{PH}_3$ and $\text{HCl}$ have the same number of electrons and similar intermolecular forces.

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