Presentation on theme: "SOLUTIONS Chapter 15. Chemcatalyst:___.___ Think back to marking period one and define in your own words the difference between a homogeneous and a heterogeneous."— Presentation transcript:
SOLUTIONS Chapter 15
Chemcatalyst:___.___ Think back to marking period one and define in your own words the difference between a homogeneous and a heterogeneous mixture?
Mixtures HOMOGENEOUS Uniform throughout 1 continual phase Example: solutions like salt water HETEROGENEOUS Not uniform throughout Multiple phases Example: Oil and water
Other Heterogeneous Mixtures: Suspension Particles are much larger Do not stay suspend indefinitely Particles begin to separate out Multiple phases Example: Clay in water or sand in water Colloids Particles are medium-sized Spread out and dispersed Cloudy or milky appearance Examples: Whipped cream, glue, milk, or mayo
Did you know? Colloidal solutions, like fog, disperse or separate light! It is called the Tyndall effect! When light passes through it, the particles reflect or scatter the light in all different directions!
Mini Lab on types
PROPERTIES OF SOLUTIONS Chapter 16
Chemcatalyst: __.__ Predict and explain whether sugar will dissolve faster in iced tea or hot tea. Follow up: Which would dissolve faster cubed sugar or granular sugar?
Solutions, eh? Solutions are homogeneous mixtures! Meaning same throughout They can be solids, liquids, or gases!
How do I make this said solution…? SOLUTE The dissolved particles in a solution is known as a solvent The solute will become dispersed throughout the solvent Can be solids, liquids, or gases SOLVENT The dissolving medium is the solvent The solvent dissolves the solute Can be solids, liquids, or gases A solution has a solute and solvent
Why do you stir sugar into your tea?
Agitation Stirring or shaking speeds up the solution process More of the solute will be brought into contact with solvent Only affects the time it takes to dissolve, not the amount of solute dissolving Insoluble will always be insoluble
Back to the C.C Hot or cold tea dissolves sugar faster?
Temperature High temperature, more kinetic energy molecules move faster The rapid motion is an increase in collisions between the solvent and the solute
Back to the C.C. follow up Sugar cube or granular sugar dissolves faster?
Particle Size of Solute The smaller the particles, the greater surface area to collide with the solvent The more surface area, more collisions and the faster rate of dissolving
Chemcatalyst __.___ What does it mean if something is soluble? Give an example
Solubility The amount of solute that dissolves in a given quantity of solvent at a given temperature and pressure This amount creates a saturated solution Solubility is expressed in g/100 g H 2 O
Supersaturated vs Unsaturated Supersaturated A solution that contains more solute that is able to dissolve Only so much will dissolve, the rest will be solid on the bottom Ex: Adding too much of the Kool Aid powder, rock candy Unsaturated A solution that contains less solute than the saturated solution Ex: Not adding enough Kool Aid Powder
Did you know? Miscible means soluble or the ability to dissolve in one another Example: Water and Ethanol Immiscible means they are insoluble Example: Oil and water
Mini Lab Solution and solubility mini lab Play at end of lab
Factors affecting solubility Temperature In general, the solubility of a solid increases as the solvent is heated In general, the solubility of a gas increases as the solvent is cooled Pressure Little effect on the solubility of solids and liquids If the pressure above the liquid increases, the solubility of the gas increases
Henry’s Law At a given temperature, the solubility of a gas in a liquid is proportional to the pressure above the liquid. If the pressure increases, the solubility increases Example: Carbonated soda (CO 2 )
Chemcatalyst: __.___ What would you need to change? A saturated solution to an unsaturated solution A saturated solution to a supersaturated solution An unsaturated solution to a saturated solution
What is concentration? The measure of the amount of solute that is dissolved in a given solvent Depending on the amount it can be classified as dilute or concentrated
Concentration Dilute solution A small amount of solute dissolved Concentrated solution Large amounts of solute dissolved *** Only qualitative, not QUANTITATIVE
If that’s qualitative, then how do we measure concentration?
Molarity (M) Molarity is the number of moles dissolved in 1 liter of solution Referred to a molar concentration or solution Units are moles/liter or represented as M ( molar) Molarity = Moles of the solute Liters of the solution ** Volume must be in liters
Let’s calculate the molarity together!
Try this one on your own:
How do you make a solution? Mini Lab
Reach question! A solution has a volume of 2.0 L and contains 36.0 grams of glucose. If the molar mass of glucose is 180 g/mol, what is the molarity of the solution? 0.10M
Chemcatalyst: __.__ What would the molarity be a solution that has moles of solute and a given volume of 400. mL? Show work with units, try your best with SF
Dilution To create a dilution, the number of moles of solution will be reduced A dilution is created from a concentrated solution We use this equation: M 1 V 1 =M 2 V 2 1 is initial conditions( concentrated solution) 2 is final conditions (dilute “new” conditions)
Let’s do this together! How many mL of 2.00 M MgSO 4 solution must be diluted to prepare a mL of M MgSO 4 ? M 1 = 2.00 M V 1 = ? mL M 2 = M V 2 = mL M 1 V 1 =M 2 V 2 (2.00 M) V 1 = (0.400 M) (100.0 mL) V 1 = 20.0 mL
Try this one on your own! How many mL of a solution of 4.00 M KI are needed to prepare mL of M KI M 1 = 4.00 M V 1 = ? mL M 2 = M V 2 = mL M 1 V 1 =M 2 V 2 (4.00 M) V 1 = (0.760 M) (250.0 mL) V 1 = 47.5 mL
Chemcatalyst: __.__ How many moles of ammonium nitrate are in 355 mL of a M solution mol How many mL of a 1.0 M solution to prepare 250. mL of a 0.20 M solution? 50. mL