Solution Found!
Estimate the time needed for a glycine molecule (see Table 13–4) to diffuse a distance
Chapter 13, Problem 71P(choose chapter or problem)
Problem 71P
Estimate the time needed for a glycine molecule (see Table 13–4) to diffuse a distance of 15 μm in water at 20°C if its concentration varies over that distance from 1.00 mol/m3 to 0.40 mol/m3. Compare this “speed” to its rms (thermal) speed. The molecular mass of glycine is about 75 u.
Table 13–4
Diffusion Constants, D (20ºC, 1 atm)
Diffusing Molecules |
Medium |
D(m2/s) |
H2 |
Air |
6.3 × 10–5 |
O2 |
Air |
1.8 × 10–5 |
O2 |
Water |
100 × 10–11 |
Blood hemoglobin |
Water |
100 × 10–11 |
Glycine (an amino acid) |
Water |
95 × 10–11 |
DNA (mass 6 × 106 u) |
Water |
0.13 × 10–11 |
Questions & Answers
QUESTION:
Problem 71P
Estimate the time needed for a glycine molecule (see Table 13–4) to diffuse a distance of 15 μm in water at 20°C if its concentration varies over that distance from 1.00 mol/m3 to 0.40 mol/m3. Compare this “speed” to its rms (thermal) speed. The molecular mass of glycine is about 75 u.
Table 13–4
Diffusion Constants, D (20ºC, 1 atm)
Diffusing Molecules |
Medium |
D(m2/s) |
H2 |
Air |
6.3 × 10–5 |
O2 |
Air |
1.8 × 10–5 |
O2 |
Water |
100 × 10–11 |
Blood hemoglobin |
Water |
100 × 10–11 |
Glycine (an amino acid) |
Water |
95 × 10–11 |
DNA (mass 6 × 106 u) |
Water |
0.13 × 10–11 |
ANSWER:
Soluition 71P
Step 1 of 3
We are required to calculate the diffusion time for a glycerine molecule.