Lacey_Che131_S2012_Lect-9s - Solutions Earths surface ~ 75 covered by 75 water depressions in Earths crust filled with 1.5 1021 L of H2O(l Lec-9

Lec-9: Solutions; concentration & dilution Roy A. Lacey, Stony Brook University; Che 131, Spring 2012 1 Solutions E th’ f 75% d b ` Earth’s surface ~ 75% covered by water; depressions in Earth’s crust filled with 1.5 × 10 21 L of H 2 O( l ). ` Properties of water responsible f lif E th d for life on Earth, and many geographical features. ` All natural waters (fresh or All natural waters (fresh or saltwater) have ionic and molecular compounds dissolved i h in them. Roy A. Lacey, Stony Brook University; Che 131, Spring 2012 2 Solutions S l ti I t t Solutions are Important Most of the Chemistry which makes life possible occ r in aq eo s sol tion occur in aqueous solution Medicine Agriculture Etc. Solution: Solute + Solvent S l S l l l C d Solute: Salts, Molecular Compounds Solvents: Water, Organic, etc Change concentration by using different Change concentration by using different amounts of solute and solvent Roy A. Lacey, Stony Brook University; Che 131, Spring 2012 3 Solutions S l i ` Solutions: • Homogeneous mixtures of two or more of two or more substances: » solvent = substance present in the greatest present in the greatest quantity » solutes = substances dissolved in the solvent ( i e i.e. , the other ingredients in the mixture) Aqueous solutions ` Aqueous solutions → water is solvent Roy A. Lacey, Stony Brook University; Che 131, Spring 2012 4