Explain the independence of surface tension on surfactant concentration above the CMC (critical micelle concentration).
Explain the independence of surface tension on surfactant concentration above the CMC (critical micelle concentration).
Surface tension of a strongly ionizable anionic surfactant at 3 x 10 -3 mol/l is 55.5 mN/m and at 3x 10 -2 mol/l is 27.5 mN/m. Assuming this region of concentration to be the linear part of the surface tension vs log concentration plot, determine the surface excess of the surfactant at the air-liquid interface.
why the molar conductance of a solution of an ionic surface agent decrease above the critical micelle concentration?
"How does a positive, neutral (zwitter) and negative amino acid effect a cationic surfactant?" Can someone please explain in details using Arginine, Isoleucine and Glutamic acid as explain? Also, how each can effect the Critical Micelle Concentration of a cationic surfactant? This is for my PCHEM lab btw.
Surfacants are molecules with a hydrophillic head group (maybe charged and a hydrophobic (nonpolar) tail. Individually, the hydrophillic head group of a surfactant could interact with water molecules through intermolecular forces and thus decrease the surface tension compared to pure water. At a certain concentration, surfactants in water can aggregate spontaneously to form micelles which has the hydrophillic head groups pointing out towards the water and the nonpolar tails are kept inward toward the micelle center. Explain in 3 sentences...
1. If you add salt in the water it will breakdown the surface tension, why? Explain. 2. Explain about the capillary action, the convex and the concave phenomena?
3. For the carburization process in problem #2 above the surface carbon concentration is at 1.0 wt% C. The initial carbon concentration of the steel is 0.2 wt%. Calculate how long it will take at 10000C to reacha carbon concentration of 0.6 wt% at a distance of 1 mm from the surface. Assume this is a semi-infinite solid. region. The density of y-iron (FCC) at 1000°C is 7.63 g/cm3, Do = 20x106 m2/s; Q = 142,000 J/mol
Explain why nonpolar molecules usually have much lower surface tension than polar ones.
Study Guide Questions 1. Explain the relationship between the kinetic energy of molecules or atoms in a system, and temperature, 2. Explain what it means when someone says, "Water is a polar molecule." (Bet you hear that all the time!) 3. What are hydrogen bonds? 4. Why is it difficult to heat up (or cool down) water? 5. Why is water such a good solvent? Are there any substances water cannot dissolve? Why or why not? 6. What is surface...
4. Nickel has normal free energy (surface tension) of 2.69 /m2 s a normal melting point of 1455 "C, enthalpy of fusion of +17.47 kJ/m, and surface a. Calculate the critical radius of nickel (in nm) at 1000 C. (2p) 2(2(28k) (17.47 : 117 XOA b. Assunning ΔGTisnegative, whatdoes negativeAhmeanfortheformation ofstablenucles? Explain. (Ip) 5. Utilizing the lead-tin phase diagram: For a 60 wr% Sn-40 wt% Pb alloy at 150 °C: a. What phase(s) is (are present? (Ip) 2 piases Present...
[Viscosity Questions] about chemistry: (multiple choice about viscosity) Please help. Thanks!! Explain each one thanks! 1. A fluid is considered "Newtonian" if: a) it experience laminar flow b) η is independent of the velocity gradient c) η is a constant d) the shearing force is exerted in the direction of the flow e) all of the above 2. The viscosity η is a function of: a) temperature b) Pressure c) composition d) volume e) a, b, and c are correct...