Skip to main content
Ch.13 - Properties of Solutions
Brown - Chemistry: The Central Science 15th Edition
Brown15th EditionChemistry: The Central ScienceISBN: 9780137542970당신이 사용하는 게 아니라요?교과서 변경
모든 교과서Brown 15th EditionCh.13 - Properties of Solutions문제 112a
13장, 문제 112a

Compounds like sodium stearate, called 'surfactants' in general, can form structures known as micelles in water, once the solution concentration reaches the value known as the critical micelle concentration (cmc). Micelles contain dozens to hundreds of molecules. The cmc depends on the substance, the solvent, and the temperature. (a) The turbidity (the amount of light scattering) of solutions increases dramatically at the cmc. Suggest an explanation. .

검증된 단계별 안내
1
Understand the concept of micelles: Micelles are spherical aggregates of surfactant molecules in a liquid colloid, where the hydrophobic tails are in the interior and the hydrophilic heads are on the exterior, interacting with water.
Recognize the role of critical micelle concentration (cmc): The cmc is the concentration of surfactants above which micelles form and below which only individual surfactant molecules are present.
Consider the effect of micelle formation on light scattering: When micelles form, they create larger structures compared to individual surfactant molecules, which can scatter light more effectively.
Relate turbidity to light scattering: Turbidity is a measure of the cloudiness or haziness of a fluid, which is directly related to the amount of light scattered by particles in the solution.
Conclude that the increase in turbidity at the cmc is due to the formation of micelles, which scatter light more than individual surfactant molecules, leading to a dramatic increase in turbidity.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
1m
도움이 되었나요?

주요 개념

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

Surfactants

Surfactants are compounds that lower the surface tension between two substances, such as oil and water. They have a hydrophilic (water-attracting) head and a hydrophobic (water-repelling) tail, allowing them to interact with both polar and nonpolar substances. This unique structure enables surfactants to aggregate in water, forming micelles when the concentration exceeds the critical micelle concentration (cmc).

Critical Micelle Concentration (cmc)

The critical micelle concentration (cmc) is the specific concentration of surfactants in a solution at which micelles begin to form. Below this concentration, surfactant molecules exist primarily as individual entities, while above it, they aggregate into micelles. The cmc is influenced by factors such as the type of surfactant, the solvent used, and the temperature of the solution.
추천 영상:
가이드 코스
07:35
Calculate Concentration of the Basic Form

Turbidity and Light Scattering

Turbidity refers to the cloudiness or haziness of a solution caused by the presence of suspended particles. In the context of micelle formation, as surfactants reach the cmc and aggregate into micelles, they scatter light more effectively due to their size and structure. This increase in light scattering results in a noticeable rise in turbidity, indicating the transition from individual surfactant molecules to organized micellar structures.
추천 영상:
가이드 코스
00:57
Speed of Light Formula
관련 실천
교과서 질문

At ordinary body temperature (37 °C), the solubility of N2 in water at ordinary atmospheric pressure (1.0 atm) is 0.015 g/L. Air is approximately 78 mol % N2. (b) At a depth of 100 ft in water, the external pressure is 4.0 atm. What is the solubility of N2 from air in blood at this pressure?

1286
views
1
comments