Solutions

Solutions Solute- the substance being put into the solution. Solvent- the substance in which the solute is being put into. Solution- the substance that results from a solute being put into a solvent. Example: Salt is a solute, Water is the solvent, Salt Water is the solution.

Types of Solutions Are all solutions liquids?! NO! Write down some examples: Solute Solvent Example Solution Gas Air Liquid Soda Juice Solid Sweet Tea Steel

Solutions Soluble versus Insoluble. Miscible versus Immiscible. Soluble – dissolved in solution. Insoluble – will not dissolve in solution. Miscible versus Immiscible. Miscible – “Mixable” able to mix together. (Ex. Water and Bleach) Immiscible – Not able to mix together. (Ex. Water and Oil)

Types of Mixtures Solution Colloid Suspension Particle Size smallest middle largest Tyndall Effect (scattering of light; or cloudy) No Yes Settles out/Filtration Mixture Type Homogeneous Heterogeneous Example Salt water Fog/Milk Muddy water

Water as the Universal Solvent What are some properties of water that make it a good solvent? Polar molecule: dissolves other polar substances IMF’s: High boiling point so it remains a liquid at room temperature and higher Most abundant liquid on earth

“likes dissolves likes” Polar substances dissolve other polar substances Nonpolar substances dissolve other nonpolar substances Polar substances do NOT dissolve nonpolar substances

Will they be soluble? CH4 and H2O NH3 and H2O

Will they be soluble? CH4 and H2O – CH4 is nonpolar, H2O is polar. They will NOT be soluble. NH3 and H2O – Both are polar. They will be soluble!

Solutions as Electrolytes Electrolyte: substances that dissolve in water to give a solution that conducts electricity Good electrolytes: substances that form IONS  ionic compounds, acids, bases Non-electrolytes: DON’T FORM IONS: most molecular compounds (COVALENT)

Electrolyte Versus Nonelectrolyte Electrolyte- Ionic compounds that dissociate (or break apart) into their charged ions. Conducts electricity Nonelectrolyte- do not dissociate therefore they don’t conduct electricity

Play the Electrolytes video from the website

Play this video as well https://www.youtube.com/watch?v=0cPFx0wFuVs&t=4s

Decide if each chemical is an electrolyte or a nonelectrolyte

Electrolyte or Nonelectrolyte? NaCl Electrolyte - Ionic

Electrolyte or Nonelectrolyte? H2SO4 Electrolyte - Acid

Electrolyte or Nonelectrolyte? CO2 Nonelectrolyte - covalent

Electrolyte or Nonelectrolyte? C6H12O6 Nonelectrolyte - covalent

Electrolyte or Nonelectrolyte? K3PO4 Electrolyte - Ionic

Electrolyte or Nonelectrolyte? CCl4 Nonelectrolyte - covalent

Electrolyte or Nonelectrolyte? Ca(OH)2 Electrolyte – ionic, base

Electrolyte or Nonelectrolyte? HCl Electrolyte - acid

Electrolyte or Nonelectrolyte? SO2 Nonelectrolyte - covalent

Electrolyte or Nonelectrolyte? KOH Electrolyte – ionic, base

The Solution Process Solvation: process by which solvent particles surround solute particles Dissociation: separation of ionic compounds into ions Hydration: Solvation with water as a solvent; ions are surrounded by water molecules and kept separate (H on the water is attracted to the negative ion; O is attracted to the positive ion)

Dissociation The separation of ions from one another.

Hydration Water molecules attach to dissolving molecules and ions.

Play this video: https://www.youtube.com/watch?v=EBfGcTAJF4o

Factors that Affect Rate of Solution Increasing surface area: the smaller the crystals, the faster it will dissolve because of the greater surface area, stirring also increases surface area and rate of solution Increasing temperature: Increases rate because particles move faster

More Factors that Affect Rate of Solution Increasing pressure: GASES ONLY, increasing pressure increases the increases the rate (Think about soda) Increasing concentration – more particles means more collisions, so rate increases Using a catalyst – speeds up the rate by lowering activation energy

Solubility Solubility refers to HOW MUCH solute can be dissolved in an amount of solvent (Different than RATE which is the SPEED at which something dissolves)

Factors that Affect Solubilty Nature of solute/solvent: Polar dissolves polar, nonpolar dissolves nonpolar, polar does NOT dissolve nonpolar Temperature: For solid and liquid solutes: increasing temperature increases solubility For gas solutes: increasing temperature decreases solubility (think about soda Pressure: GASES ONLY! Increasing pressure means MORE can dissolve (increased solubility)

Key Terms: Saturated – solution is holding the maximum amount of solute that it can hold Unsaturated – solution is holding less than the maximum amount of solute Supersaturated – solution is holding more than the maximum amount of solute

Solubility Curves Shows the amount of a solute (in grams) that will dissolve in a specific amount of water (usually 100g) at various temperatures.

Play Solubility Curves video

Try It: 1. Which substance has the highest solubility at 10°C? 2. How much KCl can 100 g of water hold at 50°C? 3. How much KCl can 300g of water hold at 50°C? 4. If a solution contains 100 g of NaNO3 at 20°C, is the solution saturated, unsaturated, or supersaturated?

Solution Concentration Concentration is a measure of the amount of solute in the amount of solvent or solution. Qualitative measures of concentration Dilute: small amount of solute compared to the amount of solvent (could be a saturated solution) Concentrated: large amount of solute compared to the amount of solvent

Play Molarity video

Molarity and Concentration Quantitative measures of concentration:

Practice Problem 1 What is the molarity of a solution containing 5.85 grams of potassium iodide in 125 mL of solution?

Practice Problem 2 How many moles of sulfuric acid are present in 500 mL of a 0.150 M solution?

Practice Problem 3 What is the mass of sodium chloride in 240 mL of a 3.00 M solution?

Play dilutions video

Diluting Solutions H2O 2M 12M M1V1=M2V2 Moles = Moles M=mol/volume ; mol= (M)(V) M1V1=M2V2

Diluting Solutions – Practice Problem What volume of 2.00M CaCl2 would you use to make 0.5L of 0.300M CaCl2?

Quiz Topics Solutions Vocab Molarity Calculations Solubility (how is it affected) Solubility Curves Saturated, Unsaturated, Supersaturated

Colligative Properties Definition: Physical properties of a solution that are affected by the number of solute particles. Four you need to know: Vapor pressure lowers Boiling point rises Freezing point lowers Osmotic pressure increases

Colligative Properites Electrolytes: NaCl(s)  Na+(aq) + Cl- (aq) Since electrolytes break apart in solution, there are more particles, and therefore a bigger effect on the colligative properties Nonelectrolytes: C12H22O11(s)  C12H22O11(aq) They don’t break apart in solution, so there are fewer particles, and a smaller effect.

Vapor Pressure Lowering Vapor pressure lowers when a solute is present, because it is more difficult for a solvent to evaporate because of the strong IMF formed between the solute and solvent

Boiling Point Elevation Adding salt (or any solute) to water increases its boiling point Increases boiling point because more imfs between solute and solvent to break before the solution boils

Freezing Point Depression Decreases freezing point because more imfs to overcome before the solution freezes

Osmotic Pressure The pressure needed to reverse or stop osmosis Osmosis: the diffusion of solvent particles across a semipermeable membrane