Chapter 13-15

The reason that CCl₄ has a higher boiling point than CF₄ is that

• CF₄ molecule have a greater polarizability
• CCl₄ molecules have a greater polarizability
• CF4 molecules are more polar
• CCl₄ molecules are more polar

At room temperature, F₂ and Cl₂ are gases, Br₂ is a liquid, and I₂ is a solid. This is because

• dipole-dipole interactions increase with molecular size
•  dipole-induced dipole interactions increase with molecular size
• dispersion interactions increase with molecular size.
•  dispersion interactions increase with molecular size and polarity increases with molecular size

Based on the following information:
CF₄, Molecular Weight 87.99, Normal Boiling Point -182°C
CCl₄, Molecular Weight 153.8, Normal Boiling Point -123°C
The intermolecular forces of attraction in the above substances is described by which of the following: 

• dispersion (or London) forces
• dipole-dipole forces (permanent dipoles)
• ion-dipole forces
• None of the above 

The boiling point of CH₄ is much lower than that of HF. This is because

• of dipole-dipole interactions in CH₄
•  HF is more polarizable
• of hydrogen bonding in HF
• of ion-dipole interactions in CH₄

Why is the normal boiling point of hydrogen fluoride is so much higher than that of hydrogen chloride, the hydride of the next element in group VIIA?

•  the electron cloud in the HF molecule is more easily distorted (i.e. is more polarizable) than that of HCl
• chlorine in HCl is more electronegative than fluorine in HF
• the HF molecules undergoes a higher degree of hydrogen bonding than HCl
•  HCl molecules are non-polar