Question

There are 10 drops of hexane in one ml, it took 39 drops to form a phospholipid bilayer, Assuming the molecules are square, what is the area of one molecule?

Answer 1

Solution :

Assume that the diameter of the watch glass is 9.5 cm.

There are 10 drops of hexagon in 1 mL.

V = volume of hexagon in per drop = $\frac{1}{10}$  mL per drop

V = 0.1 mL per drop

N = number of drops to form phospholipid layer

N = 39 (assumed)

$\bar V$ = volume of hexagon required to form phospholipid layer

$\bar V$ = V x N

$\bar V$ = 0.1 x 39  

   = 3.9 mL

Since 1 mL = 1 $cm^3$

∴  $\bar V$  = 3.9 $cm^3$

d = diameter of the watch glass = 9.5 cm

A = area of one molecule

$A=\frac{\bar V }{\pi d}$

$A=\frac{3.9 }{3.14 \times 9.5}$

$A=0.1307 \ cm^2$