Question 1

Van't Hoff's limiting law for osmotic pressure is 6 P - o6w A) J_V = Lp ($\Delta$P- $\sigma$$\Delta$$\pi$) B) $\pi$ = RT ln C C) $\pi$ =$\phi$ RT ln C D) $\pi$= RT C E) Lp = $\pi$ a⁴ / 8$\eta$ð

Accepted Answer

Van't Hoff's law for osmotic pressure is given by $\pi = RTC$, where $\pi$ is the osmotic pressure, $R$ is the gas constant, $T$ is the temperature in Kelvin, and $C$ is the molar concentration of the solute. This equation shows that the osmotic pressure is directly proportional to the concentration of the solute in the solution.

Question 2

Doubling the thickness of a microporous membrane should have what effect on pressure-driven flow across it?
A) Reduce flow to 1/2 of its previous value
B) Reduce flow to 1/4 of its previous value
C) Increase flow to 2X its previous value
D) Increase flow to 4X its previous value
E) Increase flow to 8X its previous value

Accepted Answer

Doubling the thickness of a microporous membrane increases the resistance to flow, reducing the flow rate to half of its previous value according to Darcy's law for flow through porous media.

Question 3

An approximate equation for the pressure-driven volume flow across a microporous membrane with n pores per unit area is w a2 / yð 6 P A) Q _V = n$\pi$a²/ $\eta$ð$\Delta$P B) Q_V = A n$\pi$a⁴ / 8$\eta$ð$\Delta$P C) Q_V = - AD ( $\Delta$ P - o$\delta$$\pi$)/ð D) Q_V = n $\pi$ a⁴ / 8$\eta$ð $\Delta$P E) None of the above

Accepted Answer

B

Question 4

Doubling the viscosity of a fluid that is pressure- driven across a microporous membrane should
A) Double the flow
B) Increase the flow to 16X its previous value
C) Halve the flow
D) Have little effect on the flow
E) Decre ase the flow by a factor of 4

Accepted Answer

Doubling the viscosity of a fluid generally results in halving the flow rate across a microporous membrane, assuming other conditions remain constant, according to the Hagen-Poiseuille equation for laminar flow.

Question 5

Doubling the radius of the pores in a microporous mem brane should affect pressure-driven flow by
A) Increasing it to 2X its previous value
B) Increasing it to 4X its previous value
C) Increasing it to 8X its previous value
D) Increasing it to16X its previous value
E) Increasing it to 32X its previous value

Accepted Answer

The flow through a membrane is proportional to the fourth power of the pore radius (Hagen-Poiseuille equation), so doubling the radius increases the flow by 2^4 = 16 times.

Question 6

The best predictor of the osmotic pressure is
A) Solute solubility
B) Concentration of solute
C) Concentration of water in a solution
D) Vapor pressure depression
E) The reflection coefficient

Accepted Answer

The answer of The best predictor of the osmotic pressure...

Question 7

The reflection coefficient
A) Depends on the shape and size of the solute
B) Depends on the number of pores in the membrane
C) Depends on the shape and size of the pores in the membrane
D) Determines the flow produced by a given hydrostatic pressure
E) Both A and C are correct

Accepted Answer

The reflection coefficient is influenced by the shape and size of the solute and the shape and size of the pores in the membrane. These factors determine how easily a solute can pass through a membrane, affecting the reflection coefficient.

Question 8

The coefficient that corects the observed osmotic pressure for an imperfectly semi-permeable membrane is A) $\phi$ B) $\sigma$ C) L_p D) p E) Lp $\sigma$

Accepted Answer

The coefficient that corrects the observed osmotic pressure for an imperfectly semi-permeable membrane is represented by $\sigma$, known as the reflection coefficient. This coefficient accounts for the membrane's selectivity in allowing certain solutes to pass through while reflecting others, thus affecting the observed osmotic pressure.

Question 9

Consider a microporous membrane that separates a solution on the left with concentration CL from a solutio n on the righ t at C_R. The permeability for the solute, p > 0. If C_L > C _R, the presence of pressure-driven flow from right to left should A) Increase the net flux of solute from left to right by solvent drag. B) Increase the net flux of solute from right to left by solvent drag. C) Decrease the net flux of solute from left to right by solvent drag. D) Decrease the net flux of solute from right to left by solvent drag. E) Not affect net flux of solute from left to right.

Accepted Answer

The answer of Consider a microporous membrane that separates a...

Question 10

Red blood cells were placed in a solution of 3% glucose. W e should expect
A) The rbcs swell because this solution is hypertonic
B) The rbcs swell because this solution is hypotonic
C) The rbcs shrink because this solution is hypertonic
D) The rbcs shrink because this solution is hypotonic
E) The rbcs neither shrink nor swell because this solution is isotonic

Accepted Answer

Red blood cells will swell in a hypotonic solution because the concentration of solutes (like glucose) outside the cells is lower than inside, causing water to move into the cells to balance the solute concentrations.

Question 11

Red blood cells were placed in a solution of 1.2 % NaCl. W e should expect
A) The rbcs swell because this solution is hypertonic
B) The rbcs swell because this solution is hypotonic
C) The rbcs shrink because this solution is hypertonic
D) The rbcs shrink because this solution is hypotonic
E) The rbcs neither shrink nor swell because this solution is isotonic

Accepted Answer

The solution of 1.2% NaCl is hypertonic relative to the cytoplasm of red blood cells (RBCs), which typically have a lower concentration of solutes. When RBCs are placed in a hypertonic solution, water moves out of the cells into the surrounding solution to balance the solute concentration, causing the cells to shrink.

Quiz 12: Osmosis and Osmotic Pressure

Van't Hoff's limiting law for osmotic pressure is 6 P - o6w

Doubling the thickness of a microporous membrane should have what effect on pressure-driven flow across it?

An approximate equation for the pressure-driven volume flow across a microporous membrane with n pores per unit area is w a2 / yð 6 P

Doubling the viscosity of a fluid that is pressure- driven across a microporous membrane should

Doubling the radius of the pores in a microporous mem brane should affect pressure-driven flow by

The best predictor of the osmotic pressure is

The reflection coefficient

The coefficient that corects the observed osmotic pressure for an imperfectly semi-permeable membrane is

Consider a microporous membrane that separates a solution on the left with concentration CL from a solutio n on the righ t at C R. The permeability for the solute, p > 0. If CL > C R, the presence of pressure-driven flow from right to left should

Red blood cells were placed in a solution of 3% glucose. W e should expect

Red blood cells were placed in a solution of 1.2 % NaCl. W e should expect

Consider a microporous membrane that separates a solution on the left with concentration CL from a solutio n on the righ t at C_R. The permeability for the solute, p > 0. If C_L > C _R, the presence of pressure-driven flow from right to left should