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Bell Work. How can you tell the difference between the three states of matter? Give an example of each state that is present in this room. Physical Science – Lecture 56. Mixtures and Chemical Reactions. Combining Substances. Chemical Compounds.
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Bell Work • How can you tell the difference between the three states of matter? • Give an example of each state that is present in this room.
Physical Science – Lecture 56 Mixtures and Chemical Reactions
Chemical Compounds • The combination of two or more elements that forms one substance.
Mixtures • a physical blend of two or more substances that are not chemically combined. • If the composition of a material may vary, then the material is a mixture.
Types of Mixtures • Based on the distribution of their components, mixtures can be classified as heterogeneous mixtures or homogeneous mixtures.
Heterogeneous Mixtures • A mixture in which the components are not uniform throughout.
Heterogeneous mixtures consist of two or more phases (layers, parts, phases of matter, etc).
Examples – Heterogeneous Mixtures • Fruit Salad • Red Beans and Rice • Jelly Beans • Toy Boxes • Jelly • Students in a Classroom
Homogeneous Mixtures • A mixture in which the composition is uniform throughout.
Homogeneous mixtures must consist of only one phase (layer, parts, phases of matter, etc).
Examples – Homogeneous Mixtures • Jello • Sweet Tea • Melted Cheese • Salt Water
Solutions • Another name for a homogeneous mixture is a solution. • A solution is a homogeneous mixture consisting of a solute dissolved in a solvent.
Solute • The substance dissolved in the other substance.
Solvent • The substance that the other substance is dissolved in.
Example • When you make a glass of sugar water, you take a 4 cups of sugar and dissolve it in 1 gallon of water. • What is the solute?
Example • When you make a glass of sugar water, you take a 4 cups of sugar and dissolve it in 1 gallon of water. • What is the solute? Sugar • What is the solvent?
Example • When you make a glass of sugar water, you take a 4 cups of sugar and dissolve it in 1 gallon of water. • What is the solute? Sugar • What is the solvent? Water • What is the solution?
Example • When you make a glass of sugar water, you take a 4 cups of sugar and dissolve it in 1 gallon of water. • What is the solute? Sugar • What is the solvent? Water • What is the solution? Sugar-Water
Strength of Solutions • The solubility is the amount of solute that can be dissolved in a given amount of solvent at any one temperature. • A solution is said to be unsaturated as long as more solute can be dissolved.
Dilute or Weak Solution - only a small amount of solute compared to solvent.
Concentrated Solution - A relatively large amount of solute to solvent.
Saturated Solution –The concentration of the solute in solution is the maximum possible at that temperature and pressure.
Supersaturated Solution -- a solution that contains more dissolved substance than does a saturated solution; • An example of supersaturated solution is carbonated water. If you shake the bottle, the solution will undissolve the carbonation.
Factors Effecting Solutions • Solubility is the ability of the solvent (water) to dissolve the solute (sugar). • Temperature, Pressure, and polarity of the solvent affect the solvents ability to dissolve the solute.
Increasing Temperature increases solubility. • Increasing Pressure increases solubility. • Changing a solvent can also increase solubility. • If the solute is polar, the solvent needs to be polar also. • If the solute is non-polar, the solvent needs to be non-polar as well.
Separating Mixtures • Differences in physical properties can be used to separate mixtures.
Filtration • The process that separates a solid from a liquid in a heterogeneous mixture is called filtration.
Example • How would I separate beans from a jar filled with water?
Distillation • Distillationhappens when one liquid is separated from another based on boiling points. The first liquid is boiled off, condensed, and then collected as a liquid.
