Why is the normal boiling point of hydrogen chloride so much lower than that of hydrogen fluoride?
Question 23 options:
a) HCl molecules are polar
b) HF molecules are non-polar
c) The difference in electronegativity is greatest between H and Cl
d) The forces formed between HCl molecules are weaker than between HF molecules
e) The difference in electronegativity is lowest between H and F
is the correct answer is d)?
Yes, the correct answer is d) The forces formed between HCl molecules are weaker than between HF molecules. The strength of intermolecular forces determines the boiling point of a substance. In the case of hydrogen chloride (HCl) and hydrogen fluoride (HF), HF has stronger intermolecular forces due to hydrogen bonding between the hydrogen atom in HF and the highly electronegative fluorine atom. This results in stronger attractive forces between HF molecules and a higher boiling point compared to HCl, which does not form hydrogen bonds and has weaker intermolecular forces.
Yes, the correct answer is d) The forces formed between HCl molecules are weaker than between HF molecules. The normal boiling point of a substance is determined by the strength of intermolecular forces between its molecules. In the case of hydrogen chloride (HCl) and hydrogen fluoride (HF), both molecules are polar, but HF molecules have stronger intermolecular forces due to hydrogen bonding. Hydrogen bonding is a stronger intermolecular force compared to the dipole-dipole interactions present in HCl molecules. As a result, HF requires more energy to overcome these stronger intermolecular forces and reach its boiling point, which is why its boiling point is higher compared to HCl.
Yes, the correct answer is d) The forces formed between HCl molecules are weaker than between HF molecules.
To understand why the normal boiling point of hydrogen chloride (HCl) is lower than that of hydrogen fluoride (HF), we need to consider the intermolecular forces between the molecules.
HCl and HF both have polar bonds because of the difference in electronegativity between the hydrogen and the halogen atom (chlorine and fluorine, respectively). This difference in electronegativity creates a partial positive charge on the hydrogen atom and a partial negative charge on the halogen atom.
In the case of HCl, the relatively low boiling point is due to the fact that the intermolecular forces (called dipole-dipole forces) between HCl molecules are weaker compared to the intermolecular forces between HF molecules. This weaker intermolecular force means that it takes less energy to overcome these forces and convert HCl from a liquid to a gas. Consequently, HCl's normal boiling point is lower.
In HF, the intermolecular forces are stronger because the difference in electronegativity between hydrogen and fluorine is greater than that between hydrogen and chlorine. The stronger intermolecular forces between HF molecules require more energy to break these bonds and convert HF from a liquid to a gas, resulting in a higher normal boiling point for HF compared to HCl.
So, the correct answer is d) The forces formed between HCl molecules are weaker than between HF molecules.