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?

검증된 단계별 안내

Identify the two forms of cocaine: the free-base form (C_{17}H_{21}NO_{4}) and the hydrochloride form (C_{17}H_{22}ClNO_{4}).

Understand that solubility in water is influenced by the polarity of the molecule. Polar molecules are generally more soluble in water.

Recognize that the hydrochloride form of cocaine is a salt, which typically increases its polarity and, consequently, its solubility in water.

Consider the role of the hydrochloride group (Cl^-) in the hydrochloride form, which can form ionic interactions with water, enhancing solubility.

Conclude that the hydrochloride form of cocaine is more water-soluble than the free-base form due to its ionic nature and increased polarity.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Solubility and Polarity

Solubility refers to the ability of a substance to dissolve in a solvent, which is often influenced by the polarity of the molecules involved. Polar substances tend to dissolve well in polar solvents (like water), while nonpolar substances are more soluble in nonpolar solvents. The presence of functional groups, such as -Cl in hydrochloride, can increase polarity and thus enhance water solubility.

Acid-Base Chemistry

Acid-base chemistry involves the transfer of protons (H+) between substances. In this context, the free-base form of cocaine can accept a proton from HCl to form the hydrochloride salt. This protonation alters the molecule's properties, including its solubility, as the resulting salt is typically more soluble in water due to increased ionic character.

Ionic vs. Molecular Compounds

Ionic compounds, such as hydrochloride salts, are formed from the electrostatic attraction between positively and negatively charged ions. These compounds generally have higher solubility in water compared to molecular compounds, like the free base form, which are held together by covalent bonds. The ionic nature of hydrochloride enhances its interaction with water molecules, leading to greater solubility.

관련 실천

교과서 질문

The 'free-base' form of cocaine (C₁₇H₂₁NO₄) and its protonated hydrochloride form (C₁₇H₂₁NO₄) 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 (e) How many mL of a concentrated 18.0 M HCl aqueous solution would it take to convert 1.00 kilograms (a 'kilo') of the free-base form of cocaine into its hydrochloride form?

1668

views

교과서 질문

Aerosols are important components of the atmosphere. Does the presence of aerosols in the atmosphere increase or decrease the amount of sunlight that arrives at the Earth's surface, compared to an 'aerosol-free' atmosphere? Explain your reasoning.

507

views

교과서 질문

A supersaturated solution of sucrose (C₁₂H₂₂O₁₁) is made by dissolving sucrose in hot water and slowly letting the solution cool to room temperature. After a long time, the excess sucrose crystallizes out of the solution. Indicate whether each of the following statements is true or false: (b) After the excess sucrose has crystallized out, the system is now unstable and is not in equilibrium.

1355

views