Chapter 3.5: Properties of Solutions - Key Concepts and Definitions

Solutions

homogeneous mixtures of two or more pure substances whose components are uniformly distributed on a microscopic scale

Properties of water

Polar ( negative charged on oxygen end) and losriclrt charges on hydeogen end

What does the polarity of water allow it to do

form hydrogen bonds and demonstrate both cohesive and adhesive proprieties c

Cohesion

A measure of how well similar molecules stick to each other or group together in

Why are water molecules cohesive

Because they are attracted to other water molecules

-allows it to travel through small capillaries without use of energy

Adhesiveness

a measure of how well dissimilar particles or surfaces cling to one another

-in water, adhesiveness allows it to stick to other molecules because of waters polarity

What is water considered

universal solvent

The formation of a solution from a solute and a solvent is a

Physical process and does not involve any chemical transformation

When is a solution formed

When liquid mixture consisting of one or more solutes dissolves in a solvent

Two classifications of solutes

Hydrophilic and hydrophobic

Examples of hydrophilic structure

Vitamins

Examples of hydrophobic

fats and oils

The solubility of a gas decreases

with increasing temperature

Saturated solution

Maximum possible amount of solute

Super saturated solution

Solvent contains more than max amount of solute and is produced at higher temperatures allowing more solute to dissolve than at lower temps

Concentrations of solution

The quantity of solute in given quantity of solution

Dilution

The addition of solvent (water) to decrease the concentration of solute in solution

What are the key players in transport of molecules through substrates and across membranes

Diffusion and osmosis

Diffusion

Movement of any substance from high concentration to low concentration

-ex: blood in the capillaries moving from heart to the lungs has high concentrations of CO2. This carbon dioxide will move out from the capillaries and diffuse across to the respiratory membrane into the lungs

Osmosis

Water moving from a high solvent concentration to areas of low solvent concentration

How does water move passively across a membrane

Through aquariums

Key similarities between osmosis and diffusion

Both do not require energy only kinetic energy of moving molecules (passive transport)

active transport

low to high concentration using energy