Final answer:
In a pure sample of CH3F (methyl fluoride), the main intermolecular forces are dipole-dipole attractions and hydrogen bonding due to the presence of a hydrogen atom bonded to a highly electronegative fluorine atom. London Dispersion Forces are also present but are weaker in comparison.
Step-by-step explanation:
The intermolecular forces present in a pure sample of CH3F (methyl fluoride) can be determined by examining the Lewis Dot structure. Methyl fluoride is a polar molecule owing to the electronegativity difference between the carbon (C), hydrogen (H), and fluorine (F) atoms. The molecule has a permanent dipole moment because of the C-F bond, which leads to dipole-dipole attractions.
Furthermore, since hydrogen is bonded to fluorine, which is one of the three most electronegative elements, a special type of dipole-dipole attraction known as hydrogen bonding is also present. Additionally, all molecules, regardless of their polarity, experience London Dispersion Forces (LDF), but given the size of the molecule, the LDF would be relatively weak compared to the other forces.
Therefore, the primary intermolecular forces in CH3F are dipole-dipole attractions and hydrogen bonding, along with weaker London dispersion forces.