Title:
Investigating Effects of Solute Concentration on Osmosis
Introduction:
Diffusion is a passive process in which particles move from an area of high concentration to an
area of lower concentration, while osmosis refers specifically to the movement of water across a
selectively permeable membrane. Cell membranes help regulate this movement by allowing
some substances to cross while restricting others, enabling passive transport to occur based on
concentration differences (BIO 110 Laboratory Manual, 2025). During osmosis, water naturally
moves from an area with more free water and lower solute concentration toward an area with less
free water and higher solute concentration until the solute levels become more equal (Cain et al.,
2020). These processes are essential for maintaining cellular homeostasis and stable internal
water balance. In this experiment, dialysis tubing was used as a model membrane to examine
how solute concentration influences osmotic movement. By observing mass changes in tubing
placed in known sucrose concentrations, the experiment aimed to determine the concentration of
an unknown solution based on its osmotic behavior.
Research Question:
How does solute concentration affect the direction and rate of osmosis?
Hypothesis / Prediction:
If the dialysis tubing is placed in a hypertonic environment, then its mass is expected to decrease
as water moves out. In a hypotonic environment, its mass should increase as water enters. In an
isotonic environment, little to no change in mass is expected because net water movement should
be minimal.
Variable Table:
Standardized Variables Independent Variable Dependent Variable
Tubing volume and Sucrose concentration Mass of the dialysis
sucrose concentration in beaker (0.1%, 20%, tubing measured at
inside tubing (10 mL; 40%, X%) regular time intervals
20.0%)
Time intervals (0–40
minutes)
Beaker volume (200
mL)
Investigating Effects of Solute Concentration on Osmosis
Introduction:
Diffusion is a passive process in which particles move from an area of high concentration to an
area of lower concentration, while osmosis refers specifically to the movement of water across a
selectively permeable membrane. Cell membranes help regulate this movement by allowing
some substances to cross while restricting others, enabling passive transport to occur based on
concentration differences (BIO 110 Laboratory Manual, 2025). During osmosis, water naturally
moves from an area with more free water and lower solute concentration toward an area with less
free water and higher solute concentration until the solute levels become more equal (Cain et al.,
2020). These processes are essential for maintaining cellular homeostasis and stable internal
water balance. In this experiment, dialysis tubing was used as a model membrane to examine
how solute concentration influences osmotic movement. By observing mass changes in tubing
placed in known sucrose concentrations, the experiment aimed to determine the concentration of
an unknown solution based on its osmotic behavior.
Research Question:
How does solute concentration affect the direction and rate of osmosis?
Hypothesis / Prediction:
If the dialysis tubing is placed in a hypertonic environment, then its mass is expected to decrease
as water moves out. In a hypotonic environment, its mass should increase as water enters. In an
isotonic environment, little to no change in mass is expected because net water movement should
be minimal.
Variable Table:
Standardized Variables Independent Variable Dependent Variable
Tubing volume and Sucrose concentration Mass of the dialysis
sucrose concentration in beaker (0.1%, 20%, tubing measured at
inside tubing (10 mL; 40%, X%) regular time intervals
20.0%)
Time intervals (0–40
minutes)
Beaker volume (200
mL)
