Decide and then explain why you concluded the following statements are true or false.

a) If glucose concentrations in solution A and B separated by a semi permeable membrane are the same, the net movement of water will be zero.

b) If glucose concentration in solution A is half that of solution B, twice as much water will leave solution A compared to that from solution B.

c) The osmotic pressure of a 1M solution of urea is the same as that of a 0.5M solution of sodium chloride.

a) True. If the glucose concentrations in solution A and B are the same and they are separated by a semi-permeable membrane, there will be no concentration gradient for water molecules. As a result, there will be no net movement of water across the membrane.

b) False. The movement of water across a semi-permeable membrane is determined by the difference in solute concentration, not the absolute concentration. A higher solute concentration in solution B means that there will be a higher osmotic pressure which will result in water moving from solution A to solution B, not the other way around.

c) False. Osmotic pressure depends on the number of solute particles in a solution, not just the concentration. A 1M solution of urea will dissociate into one urea molecule, whereas a 0.5M solution of sodium chloride will dissociate into one sodium ion and one chloride ion. Since the sodium chloride solution has two solute particles per molecule, it will have a higher osmotic pressure compared to the urea solution.

a) True. The movement of water across a semi-permeable membrane is driven by the concentration gradient of solutes, specifically here, glucose. If the glucose concentrations in both solution A and B are the same, then there is no concentration gradient. As a result, there will be no net movement of water across the membrane.

To conclude this, you can use the concept of osmosis. Osmosis is the movement of solvent molecules (in this case, water) from a region of lower solute concentration to a region of higher solute concentration, through a semi-permeable membrane. If the solute concentrations are the same on both sides of the membrane, the driving force for osmosis doesn't exist, and hence, there will be no net movement of water.

b) False. According to the principles of osmosis, water will move from a region of lower solute concentration to a region of higher solute concentration. If the glucose concentration in solution A is half that of solution B, it means that solution B has a higher glucose concentration. As a result, water will move from solution A to solution B. Therefore, it's incorrect to conclude that twice as much water will leave solution A compared to that from solution B. In fact, the opposite is true - more water will leave solution B compared to solution A.

To evaluate this statement, you can apply the concept of osmotic pressure. Osmotic pressure is the pressure required to prevent the movement of a solvent (water) across a semi-permeable membrane due to osmosis. In this scenario, the higher glucose concentration in solution B will lead to a higher osmotic pressure in solution B, causing more water to move from solution A to solution B.

c) True. Osmotic pressure depends on the number of solute particles (instead of the type of solute) in a solution. A 1M solution of urea and a 0.5M solution of sodium chloride both have the same number of particles per unit volume. Therefore, the osmotic pressure of these two solutions will be the same.

To conclude this, you can use the concept of osmolarity. Osmolarity is a measure of the total particle concentration in a solution. It is determined by the number of particles, rather than the specific type of solute. In this case, both the 1M solution of urea and the 0.5M solution of sodium chloride have the same osmolarity and hence, the same osmotic pressure.