What factors determine a solutions tonicity? The temperature of the solution The volume of the solution of solute to solvent The electrical gradient of the solution

Tonicity refers to the ability of a solution to affect the volume of a cell by osmosis, and it is primarily determined by the concentration of solutes in the solution relative to the concentration of solutes inside the cell. The key factors that determine a solution's tonicity include: 1. **Concentration of Solutes**: The relative concentration of solutes (such as salts, sugars, etc.) in the solution compared to the concentration of solutes inside the cell is the primary determinant of tonicity. Solutions can be classified as: - **Isotonic**: Equal solute concentration inside and outside the cell, resulting in no net movement of water. - **Hypotonic**: Lower solute concentration outside the cell, causing water to move into the cell, which may lead to swelling or bursting. - **Hypertonic**: Higher solute concentration outside the cell, causing water to move out of the cell, which may lead to shrinkage. 2. **Nature of Solutes**: The type of solutes present can also affect tonicity. For example, non-penetrating solutes (like NaCl) have a more significant impact on tonicity than penetrating solutes (like urea), which can cross the cell membrane. 3. **Cell Membrane Permeability**: The permeability of the cell membrane to specific solutes can influence how those solutes affect the cell's internal environment and, consequently, its tonicity. While the factors you mentioned (temperature, volume of solute to solvent, and electrical gradient) can influence various aspects of a solution, they are not primary determinants of tonicity: - **Temperature**: While temperature can affect the rate of diffusion and the kinetic energy of molecules, it does not directly determine tonicity. - **Volume of Solute to Solvent**: This can influence the concentration of the solution, but it is the concentration itself that is critical for determining tonicity. - **Electrical Gradient**: This can affect the movement of charged particles (ions) across membranes, but tonicity is primarily concerned with osmotic pressure due to solute concentration. In summary, the primary factors determining a solution's tonicity are the concentration and type of solutes relative to the cell's internal environment.