Write activity of osmosis in egg and dried raisins
Answers
Answer:
Explanation:
Osmosis in dried raisins:
To determine the mass percentage of water imbibed by raisins.
MATERIALS REQUIRED
A few raisins with stalk intact, blotting paper, weight box, physical balance, petri dish.
THEORY
Raisins are dehydrated grapes. These when kept in water swell up. This happens due to imbibition of water and endosmosis.
Imbibition is the adsorption of water or any other liquid by the solid particles of a substance causing it to increase in volume without forming a solution.
The solid particles which adsorb water or any other liquid are called imbibants. The liquid which is imbibed is called imbibate. The phenomenon of imbibition occurs due to presence of hydrophilic colloids. Proteins, starch and cellulose are some examples of hydrophilic substances. Different substances have different imbibing capacity. Proteins have very high imbibing capacity, starch has less imbibing capacity and cellulose is the weakest imbiber. Because of difference in imbibing capacities, proteinaceus pea seeds swell more on imbibition than starchy wheat seeds.
PROCEDURE
Select a few raisins with intact stalks and weigh them.
Now place these raisins in petri dish filled with water and cover it.
Keep the set-up undisturbed overnight.
Take out the swollen raisins from the petri dish and place them on a dry blotting paper to soak away the extra water.
Weigh the swollen raisins and note their weight.
OBSERVATIONS AND CALCULATIONS
Weight of dry raisins taken =x1 g
Weight of swollen raisins =x2 g
Weight of water imbibed by raisins = (x2 – x1 ) g = x g
Percentage of water imbibed by raisins = XX1 x 100 =………… %
RESULT
The percentage of water imbibed by raisins =……….. %
PRECAUTIONS
Raisins should be with intact stalks.
Proper care should be taken while weighing is done.
Sufficient water should be taken in petri dish for soaking raisins.
Before taking final weight, raisins should be dried with blotting paper to remove excess water.