Diffusion & Osmosis Lab Quiz Study Guide

Solute

Substance dissolving

Solvent

Liquid the solute dissolves in

Solution

Solute dissolved in solvent

Diffusion

The movement of molecules from an area of higher concentration to an area of lower concentration until equilibrium is reached

Rate of diffusion can change w/ variables such as:

• Concentration

• Temp.

• Time

• Size

Semi-permeable membrane

A layer that only certain molecules can pass through

Osmosis

Simple diffusion of water (The water molecules move through a semi-permeable membrane and NOT the solute molecules (sugar, salt, etc.) )

Tonicity

The relative concentrations of the solutes between 2 solutions

3 different types of tonicity:

hypertonic, hypotonic, and isotonic

Hypertonic

• relative to cell membrane

• outside: higher solute

• inside cell: lower solute

Hypotonic

• Relative to cell membrane

• outside: lower solute

• inside cell: higher solute

Isotonic

• Relative to cell membrane

• Equal solute concentration

Imagine that the solute (salt) is money. If you had 2 options: more money or less money…which would you choose?

Water is greedy so it will always move to the side w/ the highest concentration of solute.

If the concentration of solute is higher outside the cell then water will ____

leave it and go into the beaker (and vice versa)

If the solution is isotonic then water will not leave or enter the cell bc the concentrations are _____

equal.

What is the difference between solute and solvent molecules in a solution?