Topic 2

• Matter: matter makes up everything
• pure substance: made up of one thing. further classified into elements and compounds
• mixture: a substance made by mixing other substances together, can be classified to mechanical mixture and solution
• mechanical mixture: can clearly see substances that make up the mixture. also called heterogeneous
• solution: looks as if its all one substance. Also called homogeneous
• suspension: a cloudy mixture in which droplets of tiny peices of one substance are held within another. you can see suspended solids, suspended solids will separate if left undisturbed.
• colloid: cloudy mixture, droplets are so small that they do not separate
• foam colloid: gas in liquid
• emulsion colloid: two liquids
• gel colloid: solids in liquid
• solute: the substance that gets dissolved in the solvent
• solvent: the substance that does the dissolving of the solute
• concentrated solution: when there is a large amount of solute in the solvent
• diluted solution: When there is a small amount of solute in the solvent (watered down juice)
• concentration: tells you the amount of solute (in g or kg) dissolved in a specific amount of solvent (ml or L)
• unsaturated: a solution in which more solute could be added & dissolved in it
• saturated: a solution in which no more solute can dissolve at a given temperature. perfect amount of solute
• supersaturated: a solution that contains more of the dissolved material than could be dissolved by the solvent under normal circumstances
• saturation point: the maximum amount of solute that will dissolve in a solvent
• solubility: the maximum amount of solute you can add to a fixed volume of solvent at a given temperature
• aqueous solution: the solvent is water
• solubility changing with temperature: solubility of a solid solute in a substance increases as the temperature of the solvent increases. the reverse is true for gas, as temperature increases, the solubility of a gas in a liquid solvent decreases
• thermal pollution: power plants use water to cool their turbines, then return the water to the lake. If the temperature of the water increases, the amount of dissolved oxygen will decrease, killing fish
• 3 things that affect solubility: type of solute, type of solvent, temperature of solution
• particle model of matter #1: All matter is made up of tiny particles, Different substances are made up of different kinds of particles. Every object in any state is made up of tiny particles too tiny to see
• particle model of matter #2: The tiny particles of matter are always moving and vibrating. For solids, the movement is like wiggling in one place. For liquids, the particles are sliding around and over each other. For gasses, the movement means moving as far as the space they are in allows for
• particle model of matter #3: The particles in matter may be attracted to each other or bonded together, Some particles, such as water, have more attraction for other particles, such as salt, than for each other
• particle model of matter #4: particles have space between them. Solids have very little spaces between them compared to liquids and gasses
• Mixing Substances: When 2 substances are mixed together, the smaller particles of one substance fill in the spaces between the larger particles of the other
• 3 Factors that Affect the Rate of Dissolving: Temperature, Size of pieces, Stirring
• 1. Temperature, increasing temperature causes particles to move faster, Heat energy is transferred by the movement of particles, Because the solvent particles are moving faster, they bump into solute particles and thus make them dissolve
• 2. Size of pieces / surface area exposed: Small pieces of solute dissolve more quickly than large pieces
• 3. stirring: moves all of the particles around, Solvent particles then bump into solute particles and thus make them dissolve
• • Solid → liquid = Melting
• Liquid → gas = evaporating
• Gas → Liquid = Condensation
• Liquid → Solid = Freezing Solidifying
• Gas → Solid = Deposition
• • Solid  → Gas = Sublimation
• concentration of solutions

  A) diluted/unsaturated

  B) saturated

  C) supersaturated/concentrated