Chapter 15 Forming SolutionsChapter 15 Forming Solutions

Recall a solution is a homogeneous Recall a solution is a homogeneous mixture of a solute and a solvent.mixture of a solute and a solvent.

The substance present in the largest The substance present in the largest amount is the solvent.amount is the solvent.

The solute solvent combination can be any The solute solvent combination can be any state: solid, liquid, or gas.state: solid, liquid, or gas.

If water is the solvent, it is referred to as If water is the solvent, it is referred to as an aqueous solution.an aqueous solution.

The Dissolving ProcessThe Dissolving Process When an ionic substance dissolves water When an ionic substance dissolves water

separates the cation from the anion and separates the cation from the anion and both become the solute in the solution.both become the solute in the solution.

Soluble ionic compounds are more Soluble ionic compounds are more attracted to the polar water molecule than attracted to the polar water molecule than to the ionic complement in the crystal.to the ionic complement in the crystal.

Insoluble ionic compounds are more Insoluble ionic compounds are more attracted to each other than to the water attracted to each other than to the water molecule.molecule.

The Dissolving ProcessThe Dissolving Process

Molecular solutes dissolve in water if they Molecular solutes dissolve in water if they have similar bonding characteristics as have similar bonding characteristics as polar water.polar water.

Ethanol, CEthanol, C22HH55OH, dissolves in water OH, dissolves in water

because the O-H bond is similar in polarity because the O-H bond is similar in polarity to the O-H bond in water.to the O-H bond in water.

““Likes dissolve like”Likes dissolve like” Oil is a non-polar substance made with Oil is a non-polar substance made with

non polar bonds between C and H so it is non polar bonds between C and H so it is NOT soluble in water.NOT soluble in water.

““Dry” CleaningDry” Cleaning• Dry Cleaning uses a Dry Cleaning uses a

non-polar solvent to non-polar solvent to dissolve the dirt and dissolve the dirt and substances from substances from your clothes. Many your clothes. Many fabrics require this fabrics require this type of solvent.type of solvent.

• TetrachloroethylenTetrachloroethylenee Cl Cl22C=CClC=CCl22 is used is used for the dry cleaning for the dry cleaning of fabrics. It is non-of fabrics. It is non-polar because the polar because the molecule is molecule is symmetric and the symmetric and the electrons are shared electrons are shared more equally than in more equally than in water.water.

Concentration TermsConcentration Terms

UnsaturatedUnsaturated More solute can be put into the solution.More solute can be put into the solution.

SaturatedSaturated The maximum amount of solute is placed in The maximum amount of solute is placed in

the solution.the solution. Supersaturated Supersaturated

More than the maximum amount of solute is More than the maximum amount of solute is placed in the solution.placed in the solution.

SaturationSaturation A solution is said to be A solution is said to be saturatedsaturated when you when you

have the maximum amount of solute in the have the maximum amount of solute in the solvent.solvent.

At the point of saturation the solvent no longer At the point of saturation the solvent no longer has the availability to break apart the solute.has the availability to break apart the solute.

If more solute is placed in the solution a state If more solute is placed in the solution a state of of dynamic equilibriumdynamic equilibrium is reached. is reached.

The additional solute will dissolve, however the The additional solute will dissolve, however the dissolved solute will fall out of the solution at dissolved solute will fall out of the solution at the same rate.the same rate.

SupersaturationSupersaturation

Changing the temperature of the solution will Changing the temperature of the solution will affect the amount of solute allowed in the affect the amount of solute allowed in the solvent.solvent.

Increasing the temperature will increase the Increasing the temperature will increase the solubility of endothermic dissolving processes.solubility of endothermic dissolving processes.

Most solids are endothermic like this.Most solids are endothermic like this. Decreasing the temperature will increase the Decreasing the temperature will increase the

solubility of exothermic dissolving processes.solubility of exothermic dissolving processes. Most gases are exothermic like this.Most gases are exothermic like this. A solution becomes supersaturated by A solution becomes supersaturated by

saturating it then lowering/raising the saturating it then lowering/raising the temperature.temperature.

VitaminsVitamins Water soluble (polar) vitamins like Vitamin Water soluble (polar) vitamins like Vitamin

C are water soluble and can be taken daily C are water soluble and can be taken daily without concern. Your body excretes any without concern. Your body excretes any excess though the kidneys.excess though the kidneys.

Fat soluble (nonpolar) vitamins like Fat soluble (nonpolar) vitamins like Vitamin A are fat soluble and are stored in Vitamin A are fat soluble and are stored in the tissue. It is possible to overdose on fat the tissue. It is possible to overdose on fat soluble vitamins because your body has a soluble vitamins because your body has a harder time removing the excess.harder time removing the excess.

Follow recommended amounts!Follow recommended amounts!

HomeworkHomework

Terms Chapter 14Terms Chapter 14 Pg. 555 [4-11]Pg. 555 [4-11]