Introduction
Solutions are homogenous (everywhere the same) mixtures of substances that combine to form a single phase (generally liquid). Recall that a mixture is a physical blend of two or
more substances. Mixtures may not be always a liquid
Example Smoke in air
Solutions vs. Suspensions
A suspension is a temporary heterogeneous mixture. A type of mixture in which the different parts
spontaneously separate over time. Clay and water
Over time, the clay eventually settles to the bottom.
Parts of a Solution
There are two general parts of a solution Solvent
The primary ingredient Present in large amounts
Solute The other ingredients found in much smaller portions
The Water Connection
Water is the most common solvent.
Furthermore, any solution that contains water, as the solvent, is an aqueous solution.
Introduction
Colloids are stable heterogeneous mixtures that resemble homogenous mixtures. Colloid is derived from a Greek word meaning glue-
like. Milk is a colloid that contains globules of fat and
small lumps of protein casein. Mayonnaise is a colloid that contains water droplets
in oil.
Separation of Mixtures II
Separation of Mixtures at Home Using a filter to make coffee Evaporation that occurs when cooking
Leading to the burning of one’s food
Separation of Mixtures III
Separating Mixtures in a Lab Centrifugation
The use of a centrifuge, spinning up to 80,000 revolutions per minute and increasing the force of gravity up to ** times what is seen on earth, can separate substances found in mixtures based upon the different sizes of the molecules.
Separation of Mixtures IV
Chromatography Separation is based on
how quickly the components in the mixture is dissolved in a mobile phase solvent.
Paper chromatography is is a useful technique for separating components of a solution.
Separation of Mixtures V
Distillation Separates components
based on the boiling points One component
reaches its boiling point faster than the other(s). Is this how salt is
obtained from the ocean?
Definition
The solubility of a substance is the maximum amount of that substance that can be dissolved in a particular solvent at a particular temperature.
Solubility II
Glucose, a type of sugar, will dissolve in 100ml of H2O until a maximum amount has been added (83g)
Once the maximum has been achieved, the solution is said to be in equilibrium and is saturated.
Solubility III
A solution that is below the saturation point is described as undersaturated solution.
A solution that is above the saturation point, where added substance precipitates at the bottom is described as a supersaturated solution. Concentrated Solution.
The Soda Bottle
CO2 resides above the liquid before the bottle is opened and is in equilibrium with the gas in the liquid. The solution is at the point of saturation.
When the bottle is opened, the CO2 is no longer in equilibrium with the CO2 in the air and escapes the bottle/liquid in an attempt to reach that equilibrium point.