The average time it takes for a molecule to diffuse a distance of x cm is given by t=x^2/2d where t is the time in seconds and d is the diffusion coefficient. given that the diffusion coefficient of glucose is 5.7 x 10^-7 cm2/s, calculate the time it would take for a glucose molecule to diffuse 10 pm, which is roughly the size of a cell.

Explanation:

time to diffuse x cm is given by the relation

t = X² /2D

D = 5.7 x 10⁻⁷

t = X² / 2 x 5.7 x 10⁻⁷ = X² x 10⁷ / 11.4 s

X = 10 pm = 10 x 10⁻¹² m = 10 x 10⁻¹⁰ cm = 10⁻⁹ cm

t =( 10 ⁻⁹)² x 10⁷ / 11.4 = 10⁻¹¹ / 11.4 = 8.77 x 10⁻¹³ s

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.