Solutions, Concentration, Dilution

-combination of two or more different substances -components are easily distinguished -can separate components by physical methods Mixtures!

-components cannot be distinguished even with magnification -a homogeneous mixture Air Salt water Solutions!

Air Salt water Solution = Solute dissolved in solvent

Air Salt water Aqueous solution: Solution in which the solvent is water X

Properties of Solutions Solubility Concentration Electrical conductivity pH

Properties of Solutions Solubility Concentration Electrical conductivity pH

Solubility Soluble:Solute can dissolve in a given solvent Solubility: The maximum amount of solute that can be dissolved in a certain amount of solvent, at a certain temperature Solubility Temperature GASES Solubility SOLIDS Temperature

Concentration The amount of solute dissolved in a given amount of solution **Solution = solute + solvent + Solvent = ? ? ? Increased concentration Decreased concentration Dilution Dissolution + Solute = Evaporation = - Solvent =

How do we measure concentration? The amount of solute dissolved in a given amount of solution m = mass of solute (grams) V = volume of solution (liters) C = concentration (g/L) C = mVmV

Example #1 20g of NaCl dissolved in 500 L of solution. What is the concentration in g/L? C = mVmV

Example #2 200 mg of KCl dissolved in 75 mL of solution. What is the concentration in g/L? C = mVmV

Finding concentration in g/L Step 1: Convert all amounts into correct units  grams (g), liters (L) Step 2: Put the values into the equation Step 3: Solve for the unknown Step 4: Write out the answer

Concentration: % mass/mass The amount of grams of solute dissolved in 100 g of solution %m/m = mass of solute mass of solution X 100% mass of solute (mass of solute + mass of solvent) X 100% %m/m =

Example 1: 100 grams of solution contains 0.5 grams of solute. What is the %m/m concentration? %m/m = mass of solute mass of solution X 100%

Example 2: A pitcher of lemonade has 7000 mg of sugar dissolved in every 0.5kg of lemonade. What is the %m/m concentration? %m/m = mass of solute mass of solution X 100%

Concentration: % mass/volume The amount of grams of solute dissolved in 100 mL of solution %m/V = mass of solute volume of solution X 100% mass of solute (volume of solute + volume of solvent) X 100% %m/V =

Example 1: What is the %m/V concentration of sugar in a serving size of this solution? %m/V = mass of solute volume of solution X 100%

Example 2: A bottle of apple cider is labeled 12% sugar content. If the solution contains 6 grams of sugar, what is the volume in mL of the apple cider bottle? %m/V = mass of solute volume of solution X 100%

Concentration: % volume/volume The number of milliliters of solute dissolved in 100 mL of solution %V/V = volume of solute volume of solution X 100% volume of solute (volume of solute + volume of solvent) X 100% %V/V =

Example 1: What is the %V/V concentration of alcohol if I add 0.05 L of alcohol to 750 mL of water? %V/V = volume of solute volume of solution X 100%

Example 2: A solution labeled 20% alcohol contains 10 ml alcohol in ___ ml of water. %V/V = volume of solute volume of solution X 100%

Steps for these problems 1.What is the question looking for? 2.What variables did the question give and do I need to change the units? 3.What formula am I going to use? 4.Put the variables into the formula 5.Write out the solution