b. chemical and physical properties\n1. compare the boiling points of methanethiol and methanol. explain…

Answer and Solution according to the required format

1.

Step-by-Step Format:

Explanation:

Step1: Analyze intermolecular forces

Methanol ($CH_3OH$) has hydrogen bonding (due to $-OH$ group where $O$ is highly electronegative and $H$ is attached to it). Methanethiol ($CH_3SH$) has dipole - dipole forces (because of the difference in electronegativity between $C$ and $S$, but $S$ is less electronegative than $O$ in $-OH$) and London dispersion forces. Hydrogen bonding is a stronger intermolecular force than dipole - dipole forces.

Step2: Relate intermolecular forces to boiling point

Stronger intermolecular forces require more energy to break the intermolecular interactions and convert the liquid to gas. Since methanol has stronger intermolecular forces (hydrogen bonding) compared to methanethiol (dipole - dipole and London dispersion), the boiling point of methanol is higher than that of methanethiol.

Answer:

Methanol has a higher boiling point than methanethiol.

2.

Answer - Explanation Format:

Brief Explanations:

Thiols have a strong or unpleasant odor because the $C - S - H$ bond in thiols is less polar than the $C - O - H$ bond in alcohols. Thiols can easily form volatile sulfur - containing compounds (e.g., when oxidized) that are low - molecular - weight and can be easily detected by the human olfactory system. Alcohols, on the other hand, have stronger hydrogen bonding which makes them less volatile in the low - molecular - weight range (compared to thiols of similar molecular weight) and their odors are often less pungent as they do not form such easily - volatile, strong - smelling sulfur - based degradation or oxidation products as readily as thiols.

Answer:

Thiols often have a strong or unpleasant odor due to their ability to form volatile, easily - detected sulfur - containing compounds and their relatively weaker intermolecular forces (compared to alcohols of similar molecular weight) leading to higher volatility of low - molecular - weight thiols.

3.

Answer - Explanation Format:

Brief Explanations:

Simple thiols (e.g., $CH_3SH$) are polar. The $C - S$ bond has a significant electronegativity difference ($S$ is more electronegative than $C$). However, the polarity is less than that of alcohols (e.g., $CH_3OH$) because $O$ is more electronegative than $S$. In terms of solubility in water, simple thiols have limited solubility. The $-SH$ group can form some hydrogen bonding with water (but weaker than the $-OH$ group in alcohols due to the lower electronegativity of $S$ compared to $O$). Also, the non - polar hydrocarbon part ($R -$ group) of the thiol reduces its solubility. As the hydrocarbon chain length increases, the solubility of thiols in water decreases further.

Answer:

Simple thiols are polar but have limited solubility in water. The solubility decreases with increasing hydrocarbon chain length.