Lab5: Osmosis And Diffusion Flashcards
What does the law of diffusion states?
That molecules tends to move from areas of higher chemical potential to areas of lower chemical potential
What is the principle of chemical potential?
The greater the concentration of a dissolved substance (solute) — the higher is the chemical potential (free energy per mole) of that substance
What is the principle of simple diffusion?
Movement for higher chemical potential to lower chemical potential
What is the effect of temperature on the diffusion rate?
It increase the diffusion rate
How does the molar mass affects the rate of diffusion?
Lighter molecules diffuse more rapidly then heavier molecules
What is the name of the law that states a proportion between the rate of diffusion are the molar mass
Graham’s law
What is the equation for graham’s law?
R1/R2 = sqrt M2/M1
What is the principle of osmosis?
Movement of water molecules from high concentration of water to a lower concentration of water with the help of aquaporins
What is water potential?
Measure of chemical potential per mole of water molecules
What is a hypotonic solution?
Higher water potential outside the cell — water moves IN of the cell
What is the principle of hypertonic?
Lower water potential inside the cell — water moves IN the cell
What is the principle of isotonic?
Water potential is equal in and out of the cell — NO movement
Why does the volume of plant cell remain the same even if its in hypertonic?
Because of the presence of the cell wall
What are 2 examples of passive transport?
-diffusion
-osmosis
What difference active than passive transport?
Active transport requires energy to transport molecules while passive transport dont
Experiment A: diffusion in agar using permanganate solution
Why those the diffusion is quicker?
Name the dependent and independent variable?
Because it is in a hot environment and the molecular weight is inferior
Variable ind: temperature of each petry plates
Variable dep: the length of the radius
Experiment B: diffusion of gas in gas
What is the effect of the molar mass on the rate of the reaction?
Name the dependent and independent variable?
Higher molar mass — slower reaction
Smaller molar mass — quicker reaction
Variable ind: types of gas (molar mass for each gas)
Variable dep: distance the salt precipitate created from each side
Experiment C: Osmosis in decalcified eggs
What is the movement of water?
What is the effect of the concentration of sugar?
Name the dependent and independent variable?
-Water moves from hypotonic solution to hypertonic solution
-The higher the concentration of sugar is the less water is absorb = Slow down the osmosis
Variable ind: concentration of sugar in each solution
Variable dep: mass and volume of the egg after the experiment
Why does the egg increase in volume while the potato dont?
Because the egg is an animal cell so their is no cell wall to contain the water
Experiment D: Osmosis in potato Tuber Cores
Determine the tonicity
What is the effect of the concentration of salt?
Name the dependent and independent variable?
-hypotonic — hypertonic
*different tonicity for each solutions
-Higher concentration of salt — less water is absorbed
Variable Ind: concentration of salt in each cylinder
Variable dep: quantity of water that the potato can absorb
Why does the cell wall is so rigid and permit the not increase in volume?
Because it is made of cellulose
For the diffusion in agar: would diffusion rate be faster or slower if potassium permanganate is replaced by methylene blue?
(Molecular weight of potassium is 158 and for methylene blue 320)
Slower because methylene blue has a higher molecular weight than potassium
