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What is the critical micelle concentration (CMC) of sodium lauryl sulfate (SLS) in water at room temperature and what factors affect its value?

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The critical micelle concentration  CMC  of sodium lauryl sulfate  SLS  in water at room temperature  25C  is approximately 8-10 mM  millimolar . The CMC is the concentration at which surfactant molecules, like SLS, start to aggregate and form micelles in a solution.Several factors can affect the CMC value of SLS in water:1. Temperature: The CMC generally decreases with increasing temperature due to the increased solubility of the surfactant and the increased rate of molecular motion.2. Presence of electrolytes: The addition of electrolytes  salts  to the solution can affect the CMC. In general, the presence of electrolytes reduces the CMC due to the screening of the electrostatic repulsion between the charged head groups of the surfactant molecules.3. pH: The CMC can be influenced by the pH of the solution. For SLS, the CMC is relatively insensitive to pH changes, but for other surfactants with ionizable head groups, the CMC can be significantly affected by pH.4. Surfactant structure: The structure of the surfactant itself, such as the length and branching of the hydrocarbon chain and the nature of the head group, can influence the CMC.5. Presence of additives: The addition of other surfactants, polymers, or solutes can affect the CMC by interacting with the surfactant molecules and altering their aggregation behavior.It is important to note that the CMC value can vary depending on the specific experimental conditions and the method used to determine it.
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