Today’s Special http://mlb.mlb.com/allstar-teachers/ Secret lives of students HW check-Vocab 22 Test results Notes 22 HW I due next time Atomic size Part II

22 Mixtures PAc.1: Distinguish chemical properties of matter (including reactivity) from physical properties of matter (including boiling point, freezing/melting point, density [with density calculations], solubility, viscosity, and conductivity). PAc.4: Classify matter as a pure substance (either an element or a compound) or as a mixture (either homogeneous or heterogeneous) on the basis of its structure and/or composition. PAc.5: Explain the effects of temperature, particle size, and agitation on the rate at which a solid dissolves in a liquid.

You can’t build a reputation on what you’re going to do. Henry Ford Fact: The liquid inside young coconuts can be used as a substitute for blood plasma.

Mixture A combination of two or more substances in which each substance retains its properties Air is a mixture of nitrogen, oxygen, carbon dioxide and other gases Tap water is a mixture of water, minerals, and gases

Separating mixtures Filtration – use of filters to remove particulates Distillation – using heat and differences in boiling points to separate liquids

Purity A pure substance contains only a single element or compound

Heterogeneous/homogeneous Heterogeneous – components can be seen as individual substances; i.e. sand in water Homogenous – same composition throughout; solutions and suspensions

Solution/suspension Solution - all components in the same phase Suspension – components are in different phases, like Coke

Dissolving Solvent – the component in a solution of the greatest amount Solute – component dissolved in solvent

solution Unsaturated – can still dissolve more solute Saturated – has reached the limit on the amount of solute that can dissolve Super-saturated – solution has been “tricked” into holding more solute than is normally possible

SUPERSATURATED SOLUTION SUPERSATURATED SOLUTIONS ARE UNSTABLE AND ARE NOT IN A STATE OF DYNAMIC EQUILIBRIUM. A SUPERATURATED SOLUTION WILL CRYSTALLIZE IF DISTURBED OR SEEDED BY A SEED CRYSTAL. SLOW CRYSTALLIZATION FROM A SLIGHTLY SUPERSATURATED SOLUTION CAN PRODUCE LARGE AND VERY PURE CRYSTALS RAPID PRECIPITATION FROM A QUICKLY FORMED SUPERSATURATED SOLUTION OFTEN FORMS SMALL AND IMPURE CRYSTALS

mole A “chemist’s dozen” 6.02 x 1023 items; molecules, atoms, electrons, etc.

molarity Moles of solute per liter of solvent

Homework Read chapter and define vocabulary by next class. Chapter HW: pp. 385-387 I. Review questions2-16 even (due date: ____________) II. Exercises 2-16 even (due date: __________)

Today’s special In the heavens HW check; Q & A Super-saturated solutions Labs: Hypothesis & Conclusion Nuclear reactions revisited Solid vs. Liquid

Today’s special Turn in Lab on front table Nuclear reactions revisited Refining Iron Liquid nitrogen Lab II HW II due next time Solid vs. Liquid

Today’s special HW check; Q & A Science news Interactive periodic table Hot/Cold mixing demo Practice test (Enter answers in Smart response, write sentences & essays for next time) Test next time!

Today’s special Turn in practice test on front table Test 22: Answer MC in Smart response; turn in paper test with support sentences & Essays on front desk Vocab 23 due next time!