Question

Please answer ALL THE QUESTIONS below:

Comment of the effect of the following changes to experiment conditions. Justify using the following relationships: S = m(1−υρ)/f = v/(rω² ) where, m is the mass of the particle, υ is the partial specific volume, ρ is the density of the solvent, and ω is the angular velocity.

a. Quantitatively, what will happen to a particleʼs velocity if the rotor speed is doubled? (Note, S is a constant for a given substance at a given temperature and solvent)

b. Qualitatively, what will happen to S, if temperature is decreased from 20°C to 4°C. Justify your answer by talking about the change in solution density and viscosity. (Hints: water is most dense at 4°C, and the friction experienced by a particle is directly proportional to the solution viscosity).

3. DNA can be isolated from other biomolecules on a preparative scale by sedimenting in a cesium chloride density gradient. This technique exploits the fact that molecules will only sediment if the mass of the displaced solvent is less than the mass of the sedimenting particle. If the partial specific volume of DNA is 0.58 ml/g, what is the density of the solvent at the point the DNA stops sedimenting?

Answer 1