Describe the differences between the boiling and melting points of different alcohols.

The boiling and melting points of alcohols vary depending on their molecular size and intermolecular forces.

The boiling point of an alcohol increases with the increase in molecular size and the strength of intermolecular forces. This is because larger molecules have more electrons and can form stronger London dispersion forces. Similarly, alcohols with more polar functional groups, such as hydroxyl (-OH), can form stronger hydrogen bonds, leading to higher boiling points. For example, methanol has a boiling point of 64.7°C, whereas ethanol has a boiling point of 78.3°C.

The melting point of an alcohol also depends on its molecular size and intermolecular forces. However, it is also affected by the arrangement of molecules in the solid state. Alcohols with smaller molecules tend to have lower melting points because they can pack more closely together in the solid state. For example, methanol has a melting point of -97.6°C, whereas ethanol has a melting point of -114.1°C.

In general, primary alcohols have higher boiling and melting points than secondary and tertiary alcohols due to the presence of a more significant polar functional group. Additionally, branched alcohols have lower boiling and melting points than their straight-chain counterparts due to their decreased surface area and weaker intermolecular forces.

Overall, the boiling and melting points of alcohols are determined by a combination of molecular size, polarity, and intermolecular forces.