The 'free-base' form of cocaine (C17H21NO4) and its protonated hy...

Question

The 'free-base' form of cocaine (C17H21NO4) and its protonated hydrochloride form (C17H22ClNO4) are shown below; the free-base form can be converted to the hydrochloride form with one equivalent of HCl. For clarity, not all the carbon and hydrogen atoms are shown; each vertex represents a carbon atom with the appropriate number of hydrogen atoms so that each carbon makes four bonds to other atoms

(a) One of these forms of cocaine is relatively water-soluble: which form, the free base or the hydrochloride?

Accepted Answer

welcome back everyone in this example, we have Dyke Lovren which is also known as die cyclamen, a drug used to cure gastrointestinal tract spasms. The conversion of the free based form of decluttering to the protein ated hydrochloride form using one equivalent of hydrochloric acid is shown below. Note that not all carbons and hydrogen are shown and that each corner represents a carbon atom bonded to the correct number of hydrogen in order to make a total of four bonds. So this carbon here would be bonded to two hydrogen atoms where it's also bonded to these two carbon atoms. For its total of four bonds stable or to keep the carbon atoms staple. Were asked based on the given structure, determine which form of dice take Lovering is more soluble in water. And we want to make note of the fact that water is a polar molecule. So we want to figure out which form of Dick Lovren has the strongest inter molecular forces for our first structure. We can easily see that we have dipole dipole forces where we have for example, the nitrogen atom here compared to its bonds to carbon in the structure because we recognize that nitrogen is more electro negative than carbon based on our electro negativity trend, which we should recall increases as we go towards the top right of our periodic table towards flooring. Therefore nitrogen because it's more electro negative will have a slightly negative charge and our carbon atoms will have a slightly positive charge, creating this dipole dipole force as our inter molecular forces in our Dick Lovering. Now moving on to our decluttering hydrochloride. We can see that we have an ion specifically a caddy on charge on this nitrogen atom here. And we should recall that decluttering hydrochloride is actually a salt because it's considered an ionic compound which explains that positive charge on the nitrogen there. So because it's considered assault, we possibly have ion dipole interaction which is a very strong inter molecular force stronger than dipole dipole. We also should recognize that we have a hydrogen atom in our structure, meaning we have hydrogen bonding as our second inter molecular force. So we have h bonding And recall that hydrogen bonding is also one of the stronger inter molecular forces. And then of course on top of all of this we definitely have our dipole dipole forces. And because we have these three total very strong inter molecular forces associated with our dike Lovering hydrochloride, we're going to confirm that it will have a even greater polarity than dike Lovering and so it's going to be more soluble in water. So our final answer is going to be that the dike Lovering hydrochloride is going to be more soluble in water due to its presence of these three outlined inter molecular forces. I hope everything I explained was clear what's highlighted in yellow is our final answer. If you have any questions leave them down below and I'll see everyone in the next practice video

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