I do not know how to rank the polarity between these, i have also included the boiling point in degrees C but it still does not help. The only thing that i think is that D is the least polar because it is symmetrical, and i think A is the most but I'm not sure about the rest. Thank you for your help!
Rank order of polarity from least to greatest:
A) benzoic acid 246.2
B) benzaldehyde 178.1
C) benzyl alcohol 205
D) Naphthalene 218
Here is a good web site.
http://www.elmhurst.edu/~chm/vchembook/213organicfcgp.html
Here is the line you should focus on.
Amide > Acid > Alcohol > Ketone ~ Aldehyde > Amine > Ester > Ether > Alkane
To rank the polarity of the given compounds, you can consider the functional groups present in each compound. Polarity is influenced by the presence of electronegative elements or groups, as they tend to attract electrons towards themselves.
Here is a step-by-step approach to ranking the polarity of the given compounds:
1. Benzoic acid (A): It contains a carboxylic acid functional group (-COOH). This group is highly polar due to the presence of two electronegative oxygen atoms. Hence, benzoic acid is expected to be relatively polar.
2. Benzaldehyde (B): It contains an aldehyde functional group (-CHO). The carbonyl group is relatively polar due to the presence of an electronegative oxygen atom, but it is less polar compared to the carboxylic acid group. Therefore, benzaldehyde is expected to be less polar than benzoic acid.
3. Benzyl alcohol (C): It contains an alcohol functional group (-OH). The hydroxyl group is polar, as oxygen is more electronegative than carbon. However, it is typically less polar than both the carboxylic acid and aldehyde groups. Thus, benzyl alcohol is expected to be less polar than benzoic acid and benzaldehyde.
4. Naphthalene (D): Naphthalene is a hydrocarbon and does not contain any functional groups that strongly contribute to its polarity. It is a nonpolar molecule due to the symmetrical arrangement of carbon and hydrogen atoms, making it the least polar compound among the given choices.
Ranking the compounds based on polarity from least to greatest:
D) Naphthalene (least polar)
B) Benzaldehyde
C) Benzyl alcohol
A) Benzoic acid (most polar)
Note: Although boiling points can provide some information about the polarity of compounds, it is not sufficient for definitive ranking. Hence, it is more reliable to consider the functional groups present.
To rank the polarity of these compounds, you can consider a few factors like molecular structure, functional groups, and electronegativity.
1. Molecular structure: Symmetry can impact a compound's polarity. Generally, symmetric molecules tend to be nonpolar, while asymmetric molecules are usually more polar.
2. Functional groups: The presence of functional groups that are polar or have polar bonds can increase a compound's polarity. Functional groups like -OH (alcohol) and -COOH (carboxylic acid) are polar.
3. Electronegativity: Electronegativity is the ability of an atom to attract electrons towards itself in a chemical bond. Higher electronegativity values indicate more polar bonds. You can refer to periodic tables to determine the relative electronegativity of the elements involved in the compound.
Now, let's apply these principles to rank the compounds:
D) Naphthalene: Naphthalene is a symmetric aromatic hydrocarbon, so it tends to be less polar compared to the other compounds.
A) Benzoic acid: Benzoic acid contains a carboxylic acid functional group (-COOH), which is polar. It is likely more polar than naphthalene.
C) Benzyl alcohol: Benzyl alcohol contains an alcohol functional group (-OH), which is also polar. It may have slightly higher polarity than benzoic acid due to the absence of the carboxylic acid group.
B) Benzaldehyde: Benzaldehyde has a polar carbonyl group (C=O) attached to an aromatic ring. The polar carbonyl group increases the compound's polarity further compared to benzyl alcohol.
Therefore, the rank order of polarity from least to greatest would be: D) Naphthalene, A) Benzoic acid, C) Benzyl alcohol, and B) Benzaldehyde.