Sodium dodecyl sulfate (SDS) has the structure below. The surface tension of water changes as SDS is added, as shown in the graph below.

Question

(a) Why does the surface tension of water change as SDS is added?

The number of micelles increases, which allows the non-polar tails of SDS to clump together and not interact with the water
The SDS will segregate to the surface to replace the unsatisfied bonds of water molecules with the hydrophilic heads of the surfactant
The hyrophobic tails of the SDS interact with the water so that air doesn't have to
The SDS makes the solution turbid, which decreases the surface energy
(b) Which of the following images BEST represents how the molecules in solution will look at a molar concentration of 0.004?

(c) Which of the following images BEST represents how the molecules in solution will look at a molar concentration of 0.01?

Answer 1

a-2 OK
b-3 NOK
c-2 NOK

Answer 2

b and c are wrong

Answer 3

B-1
C-5

Answer 4

c 4

Answer 5

a 1
b 2
c 5
are the correct ones

Answer 6

a-2
b-1
c-5