Arrange the following compounds in order of decreasing ease of elution from a column of silica gel: a) 2-octanol; b) 1,3-dichlorobenzene; c) tert-butylcyclohexane; d) benzoic acid

Oh, we're talking about elution now, huh? Well, let me tell you, it's like a race down the column of silica gel!

In terms of ease of elution from the column, let's line them up:

First in line we have benzoic acid. This compound loves to hang out with the silica gel, so it has a harder time eluting. It's like trying to convince a couch potato to leave their comfy spot!

Next up we have 1,3-dichlorobenzene. It's not as fond of the silica gel as benzoic acid, but still takes a bit of convincing to leave. It's like getting someone to leave a really interesting TV show halfway through!

In the middle of the pack, we have tert-butylcyclohexane. It's like a cool cat that slides down the column with a bit more ease, but not as easily as the next one!

And finally, leading the pack, we have 2-octanol! This compound wants nothing to do with the silica gel. It's like running down the column with a burst of energy, leaving the others in the dust!

So, the order of decreasing ease of elution would be: 2-octanol, tert-butylcyclohexane, 1,3-dichlorobenzene, benzoic acid.

To determine the order of decreasing ease of elution, we can consider the polarity and the strength of the intermolecular forces for each compound. Generally, compounds that are more polar and have weaker intermolecular forces will elute more easily from a column of silica gel.

Let's analyze each compound and rank them accordingly:

a) 2-octanol: 2-octanol is a relatively polar compound due to the presence of the hydroxyl group (-OH). It can form hydrogen bonds with the silica gel stationary phase, making it less likely to be eluted quickly. Therefore, it will have a lower elution ease compared to other compounds.

b) 1,3-dichlorobenzene: 1,3-dichlorobenzene is a nonpolar compound with chlorine atoms attached to a benzene ring. Although chloro-substituted compounds are more polar than benzene, 1,3-dichlorobenzene does not have any hydrogen bond donors or acceptors, reducing its interactions with the silica gel. Thus, it will be eluted more easily compared to 2-octanol.

c) tert-butylcyclohexane: tert-butylcyclohexane is a nonpolar compound that lacks any functional groups with polarity. As a result, it will have weaker interactions with the silica gel and will elute more easily than 1,3-dichlorobenzene.

d) benzoic acid: Benzoic acid is a polar compound containing a carboxylic acid group (-COOH). This functional group can form hydrogen bonds with the silica gel, leading to stronger interactions and a slower elution compared to the other compounds.

Therefore, the compounds can be ranked in the following order of decreasing ease of elution from a column of silica gel:

1) tert-butylcyclohexane
2) 1,3-dichlorobenzene
3) 2-octanol
4) benzoic acid

To determine the order of decreasing ease of elution from a column of silica gel for the given compounds, we need to consider their polarity. Silica gel is a polar stationary phase, where more polar compounds tend to elute slower compared to less polar compounds.

1. Benzoic acid: It is the most polar compound among the given options due to the presence of the carboxyl group (-COOH). The presence of this highly polar group makes benzoic acid strongly interact with the polar silica gel surface, resulting in a slower elution rate. Therefore, it is expected to have the least ease of elution.

2. 1,3-Dichlorobenzene: This compound is less polar compared to benzoic acid. Though it has chlorine substituents, they are non-polar in nature. Therefore, it will have a relatively easier elution than benzoic acid but slower than other less polar compounds.

3. 2-Octanol: It is a moderately polar compound. The presence of the hydroxyl group (-OH) makes it more polar than 1,3-dichlorobenzene. However, it is less polar than benzoic acid due to the absence of a strong polar group like carboxyl. Hence, it will elute faster compared to benzoic acid but slower than tert-butylcyclohexane.

4. tert-Butylcyclohexane: This compound is the least polar among the four options. It lacks any significantly polar functional groups, making it more nonpolar compared to the others. As a result, it will have the greatest ease of elution from the column.

Therefore, the order of decreasing ease of elution from a column of silica gel for the given compounds is:
tert-butylcyclohexane > 2-octanol > 1,3-dichlorobenzene > benzoic acid.