The critical micelle concentration CMC of sodium dodecyl sulfate SDS in a 0.1 M NaCl solution is approximately 1-2 mM. The presence of NaCl in the solution reduces the CMC of SDS compared to its value in pure water around 8 mM due to the screening of electrostatic repulsion between the negatively charged sulfate head groups of SDS.The CMC of SDS is temperature-dependent. As the temperature increases, the CMC generally decreases. This is because the hydrophobic effect, which drives micelle formation, becomes stronger at higher temperatures. The exact relationship between temperature and CMC can be determined experimentally, as it depends on the specific conditions and the presence of other solutes in the solution.