Chapter 14 Mixtures and Solutions Mixtures have 2 or more substances physically combined. There are 2 main types of mixtures… Heterogeneous mixtures are those that have 2 or more visible phases or parts. Homogeneous mixtures are uniform and do not have 2 visible phases…homogeneous mixtures can also be called solutions.

Heterogeneous Mixtures A suspension has the largest particle size can be filtered, and will settle out given time… it also demonstrates the Tyndall effect.( Light reflects off of its particles visibly.) Some mixtures separate into a solid on the bottom and water on top…they are called thixotropic mixtures. Colloids are made up of medium-sized particles and do not settle out, nor can they be filtered and separated.

Brownian Motion Brownian motion is the constant movement of molecules that causes particles to stay suspended.

Solutions Solutions have 2 main parts…. The solvent is the part that does the dissolving. The solute is the part that gets dissolved. Solutions can be gas, liquid or solid.

Formation of Solutions Substances that form solutions readily are said to be soluble. If two liquids form a solution, they are said to be miscible. A substance that does not dissolve is called insoluble…if it is a liquid, it is imiscible.

14-2 Solution Concentrations The concentration of a solution is the amount of solute per quantity of solvent. Common concentration methods include… Percent by mass Percent by volume Molarity Molality Mole fraction

Percent by Mass and Volume % m/v means percent of mass per volume. To calculate this, you use the formula… %m/v= mass of solute x 100 total mass of solution % v/v means percent of solute vol./solution vol. %v/v= volume of solute x 100 total volume of solution

Molarity Molarity is a measure of moles/liter of solution. M= mole solute/liter of solution (Know this…not in PUI) When diluting molar solutions use M1V1= M2V2,. You should be able to solve these problems and also explain in a statement how to prepare them. Example…How would you prepare 500 mL of a 2.0 M solution from a stock solution of 12.0M?

Molality m= molality= moles of solute kg of solvent Example: What is the molality of a solution with 100. mL of water mixed with 58.5 grams of NaCl? Solution: 58.5 g of NaCl= 1.00 mole NaCl, so 1.00 moles NaCl = 10.0 m .100 kg of water

Mole Fraction Mole fraction = moles of A moles of A+B And…. moles of B Example: What is the mole fraction of 36.0 g of water mixed with 117 g of NaCl…. Solution: This is 3.00 moles of water mixed with 2.00 moles of NaCl, so the mole fractions are… 2.00 mol/5.00 moles for NaCl ( or .400) and 3.00 moles/5.00 moles for water(or .600)