Water is a polar solvent and carbon tetrachloride (CCl₄

Question

Water is a polar solvent and carbon tetrachloride (CCl₄) is a nonpolar solvent. In which solvent is each of the following, which is found or used in the body, more likely to be soluble?

d. cholesterol (lipid), nonpolar

Accepted Answer

Welcome back, everyone consider the following solvents, water which is polar and chloroform C H C L three, which is nonpolar, determine in which solvent retinol vitamin A and nutrient used in the body is more likely soluble. We're going to recall that when we have substances with similar polarity, we're going to recall the phrase like dissolves like where substances with similar polarity will dissolve one another. So we're comparing water which is our polar solvent to chloroform C H C L three which we understand is nonpolar. We can understand that water is polar. Because if we visualize its molecular structure, we have two hydrogens bonded to a central oxygen where oxygen has two sets of lone pairs on itself. And we have because hydrogen being less electron negative than oxygen, we would have partial positive charges on our hydrogen atoms and oxygen being more electron negative than oxygen. Sorry oxygen being more electron negative than hydrogen would have a partially negative charge on itself, creating a net dipole due to the asymmetry of our structure which is bent. So in comparison, we have chloroform where carbon in the center is bonded to hydrogen as well as three bonds to chlorine. And we have this tetrahedral structure note that chlorine are going to be more electron negative than carbon and hydrogen and will have partial negative charges. Whereas our carbon or sorry, our hydrogen being less electron negative than all of our other atoms will have a partially positive charge on itself. Now note that our dipoles for our carbon chlorine bonds would be partially canceled due to the symmetry we have in the bottom half of our tetrahedral structure. However, we would be left with the partial negative on our carbon compared to its partial positive charge on hydrogen or on its bond to hydrogen. And that leaves us with one dipole left. However, we're going to recall that the absolute value of our dipole moment which we expressed by me for our carbon hydrogen bond is going to be less than the absolute value of our dipole moment of water. And so therefore, our compound is nonpolar for chloroform. Now that we understand the polarity of these two molecules, we need to consider our molecule of retinol. So we'll draw retinol below where we have a ring structure, a pi bond or double bond. And we have two methyl groups to one carbon on our ring where we have two C H threes and a third methyl group on one of the carbons where our pi bond is located in our rink and then also bonded to the second carbon on our pi bond of our ring, we have an alkyl chain of nine carbons. So that's 123456789, where that ninth carbon is bonded to a alcohol group O H. And in this alkyl chain, our third carbon is bonded to a methyl group H three C and our seventh carbon is bonded to a methyl group as well. And just to make one correction, this carbon should be bonded so that we have its methyl group as H three C note that in this alkyl chain, we also have pi bonds because our carbon should have four bonds. So we have alternating pi bonds where we have a carbon be or sorry, a pi bond between carbons one and two. In the al chain, carbons three and four in the al chain five and six, we have a pipe bo and then at carbons seven and eight, we have a pi bond as well. So this completes our structure of retinol or vitamin A. And we can notice that a majority of this molecule consists of hydrocarbon chains consisting of carbon and hydrogen atoms. And because retinol consists of hydrocarbon chains, we would categorize retinol as a fat, specifically a fat soluble vitamin. Now, because we noted above that our net or rather our absolute value of our dipole moment of a carbon hydrogen bond is significantly less than the absolute value of our dipole moment of our water molecule, which is polar if our retinol molecule consists of hydrocarbon chains mainly making it fat soluble. Then we can say that it's therefore going to also be nonpolar. And so because it's nonpolar if like dissolves like then therefore retinol or vitamin A is most soluble in chloroform C H C L three. And this statement would be our final answer to complete this example that retinol is most likely soluble in chloroform. So I hope that this made sense and let us know if you have any questions.

Water is a polar solvent and carbon tetrachloride (CCl₄) is a nonpolar solvent. In which solvent is each of the following, which is found or used in the body, more likely to be soluble?
d. cholesterol (lipid), nonpolar

Key Concepts

Polarity of Solvents

Solubility Principles

Cholesterol and Lipids

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