Ch. 6 - Solutions I. How Solutions Form  Definitions  Types of Solutions  Dissolving  Rate of Dissolving Dec

A. Definitions  Suspension -  Suspension - heterogeneous mixture Not always evenly mixed Not always evenly mixed Mixture where particles can be separated by filtering OR settling Mixture where particles can be separated by filtering OR settling

A. Definitions  Solution -  Solution - homogeneous mixture Solvent Solvent – substance present in greater amount Solute Solute - substance being dissolved

A. Definitions Solute NaCl Solvent H 2 O Usually transparent

B. Types of Solutions All solid-liquid-gas combos are possible  Solid solution EX: dental amalgam (alloy of silver, mercury, etc.) liquid solute solid solvent

A. Definitions  Colloid –  Colloid – mixture with small undissolved particles that DO NOT settle out Particles big enough to affect light Particles big enough to affect light Usually opaque (can’t see through) Usually opaque (can’t see through)

A. Definitions

C. Dissolving  Solvation – the process of dissolving occurs at the surface of the solute solvent particles surround solute particles (+/- attraction) solute particles are pulled into solution

C. Dissolving NaCl dissolving in water

D. Rate of Solution  Solids dissolve faster with... more stirring small particle size (increased surface area) high temperatures

D. Rate of Solution  Gases dissolve faster... no shaking or stirring high pressure low temperature

E. Effects of Solution  Dissolved particles get in the way of forming crystals Lower Freezing Points!!!

E. Effects of Solution Use  Engine Coolant Higher Boiling Points!!!

MN Standards  Explain the interactions between solutes and solvents, and give examples of soluble and insoluble mixtures of materials.  (Examples: slurries, suspensions, aerosols, alloys)  Describe the dissolving process at the molecular level by using the concept of random molecular motion.  Describe how temperature, pressure, and surface area affect the dissolving process.  2.5 Student will demonstrate an understanding of chemical and physicalchanges of matter.