Question

permeable to the dialysis "membrane." e olute for today's lab is sucrose, which is not Osmosis Procedure 1. Fill four beakers with the following Beaker A: 200 ml of water Beaker B: 200 ml of water Beaker C: 200 ml of 30% sucrose solution Beaker D: 200 ml of water 2. Fill four dialysis bags with the following: Bag A: 10 ml of water Bag B: 10 ml of 30% sucrose Bag C: 10 ml of water Bag D: 10 ml of 15% sucrose 3. Weigh all bags to the nearest tenth of a gram. Record these initial weights in the table on page 34. 4. Place each bag in its respective beaker. 5. Take the bags out and record their weights every 15 minutes for 1 hour. So you will have weights for 0 time, 15 min., 30 min., 45 min., and 60 min. Record the data in the table on page 34. During your first waiting period, complete steps 1 and 2: 1. Identify each bag as isotonic, hypertonic, or hypotonic. BAG A: BAG B: BAG C: BAG D:

Answer 1

1. BAG A: The semi-permeable dialysis bag is isotonic as there is no solute present in the bag. There is 100% water in both bag and beaker. As the beaker has water and the bag has water, there is no solute concentration difference between the two solutions.

ISOTONIC

BAG B: The solute (sucrose) concentration in the bag is high in the bag as compared to the outside water in the beaker. There is 70% water in the bag and 100% water in the beaker. Hence, water will enter the bag. Hence, the bag is hypertonic but the beaker is hypotonic.

HYPERTONIC

BAG C: The solute (sucrose) concentration is higher in the beaker as compared to the water in the bag. There is 70% water in the beaker and 100% water in the bag. Hence, the bag is hypotonic but the beaker is hypertonic.

HYPOTONIC

BAG D: The solute (sucrose) concentration in the bag is high in the bag as compared to the outside water in the beaker. There is 85% water in the bag and 100% water in the beaker. Hence, water will enter the bag. Hence, the bag is hypertonic but the beaker is hypotonic.

HYPERTONIC