The critical micelle concentration CMC of Sodium Dodecyl Sulfate SDS in water is approximately 8.2 mM millimolar at 25C. The CMC is the concentration at which surfactant molecules, such as SDS, start to aggregate and form micelles in a solution.Several factors can affect the CMC value of SDS in water:1. Temperature: The CMC of SDS generally decreases with increasing temperature. This is because the hydrophobic effect, which drives micelle formation, becomes more pronounced at higher temperatures.2. Ionic strength: The presence of salts in the solution can affect the CMC of SDS. Generally, increasing the ionic strength of the solution leads to a decrease in the CMC, as the electrostatic repulsion between the charged head groups of SDS molecules is reduced.3. Presence of additives: The addition of other surfactants, polymers, or solutes can also influence the CMC of SDS. These additives can either increase or decrease the CMC, depending on their specific interactions with SDS molecules.4. pH: The CMC of SDS can be affected by the pH of the solution, as the ionization state of the sulfate head group may change with pH. However, this effect is generally minor for SDS, as its pKa the pH at which half of the molecules are ionized is very low, around 2.5. Pressure: Changes in pressure can also influence the CMC of SDS, although this effect is typically less significant than the other factors mentioned above.