Question

Both compounds are arranged in order of their: (A) Acidic strength (B) Boiling point (C) Dipole moment (D) Solubility in \(\mathrm{H}_{2} \mathrm{O}\)

Short answer

To arrange the generic compounds A and B based on their properties, follow these steps: 1. Compare their acidic strength by analyzing their chemical structure and the stability of their conjugate bases after donating a proton. 2. Compare their boiling points by considering factors such as molecular weight and intermolecular forces. 3. Analyze their dipole moments by evaluating the electronegativity difference between atoms and the orientation of individual dipole moments in the molecules. 4. Compare their solubility in water by considering the presence of polar or ionic groups in the molecules that can interact with water molecules. Arrange the compounds based on the analyzed properties, with the compound having the stronger property (higher acidic strength, higher boiling point, higher dipole moment, or higher solubility) mentioned first.

Step-by-step solution

Understand the compounds' properties and compare their acidic strength

To understand the acidic strength of compounds A and B, first, analyze their chemical structure. Identify any acidic groups, such as -OH (alcohols), -COOH (carboxylic acids), or others. Based on the compound's structure, determine the acidity by estimating the stability of the conjugate base formed after donating a proton. Compare the acidic strengths of both compounds. If one compound is more acidic, arrange them appropriately with the more acidic compound first.

Compare the compounds' boiling points

Evaluate the boiling points of compound A and B by considering factors such as molecular weight, intermolecular forces (such as hydrogen bonding or Van der Waals forces), and the overall structure of the molecules. Compare the boiling points of both compounds. Arrange the compounds appropriately, with the one with a higher boiling point first.

Analyze the compounds' dipole moments

Calculate the dipole moment of each compound by considering factors like electronegativity differences between atoms and the orientation of individual dipole moments in the molecule. A larger dipole moment indicates a greater separation of charge within the molecule. Compare the dipole moments of both compounds and arrange them accordingly, with the compound having a higher dipole moment mentioned first.

Compare the solubility of the compounds in water

Evaluate the solubility of compound A and B in water. The solubility mainly depends on the presence of polar or ionic groups in the molecule that can interact with water molecules via hydrogen bonding or ion-dipole interactions. Compounds with more polar or ionic character will have a higher solubility in water. Compare both compounds' solubility in water and arrange them accordingly, with the compound having a higher solubility in water first. At the end of this analysis, with the given compounds A and B, arrange them in order based on the properties (acidic strength, boiling point, dipole moment, and solubility in water) as discussed in the respective steps.

Key concepts

Acidic Strength

Acidic strength in organic compounds is determined by how easily a compound can donate a proton. The key factor to look at is the stability of the conjugate base that forms after this donation. For instance, in functional groups like -COOH (carboxylic acids), the resulting conjugate base is quite stable because of resonance. This makes carboxylic acids more acidic. On the other hand, -OH groups in alcohols form less stable conjugate bases, meaning they are less acidic.
To compare the acidity between two compounds:

• Identify the acidic functional groups.
• Evaluate the stability of the conjugate base.
• Consider other structural factors such as electronegativity and resonance.

Choose the compound with the more stable conjugate base as having greater acidic strength.

Boiling Point

Boiling point is influenced by the nature of intermolecular forces and the molecular weight of the compounds. Greater intermolecular forces, like hydrogen bonding, significantly increase the boiling point. For example, alcohols which can form hydrogen bonds generally have higher boiling points compared to hydrocarbons of similar molecular weight that only exhibit London dispersion forces.
When comparing the boiling points of two compounds:

• First, consider any potential for hydrogen bonding, dipole-dipole interactions, or Van der Waals forces.
• Then, examine the molecular weight—heavier molecules tend to have higher boiling points.

Arrange the compounds with stronger intermolecular forces and higher molecular weights higher in terms of boiling point.

Dipole Moment

The dipole moment of a molecule indicates the distribution of electrical charge over the molecule. It is influenced by differences in electronegativity between atoms and the geometric orientation of these polar bonds. A larger dipole moment means there is a greater separation of positive and negative charges, which can affect properties like solubility and boiling point.
When analyzing dipole moments:

• Examine each polar bond in the molecule.
• Consider the geometry to see how these vectors add up.
• Check whether the compound’s symmetry cancels out these dipoles.

Thus, a compound with a higher dipole moment will often exhibit greater interactions with other polar substances.

Solubility in Water

Solubility in water is largely determined by a compound's polarity. Water is a polar solvent, so compounds that can form hydrogen bonds or exhibit ion-dipole interactions with water molecules will dissolve more easily. Nonpolar compounds, however, won't mix well with water due to their lack of electrostatic interactions.
To evaluate a compound's solubility in water:

• Look for polar functional groups or ionic charges that can interact with water.
• Consider the molecule's ability to form hydrogen bonds.
• Remember "like dissolves like"—polar compounds will generally dissolve in polar solvents like water.

Compounds with more polar groups or ionic charges are more soluble in water.