Chapter 13 with video Notes

Chapter 13.1 and 13.2 Notes: Types of Mixtures and The Solution Process: 

Chapter 13.1 and 13.2 Notes: Types of Mixtures and The Solution Process

Types of Mixtures- Solutions: 

Types of Mixtures- Solutions Solutions - homogeneous mixtures of two or more substances in a single phase. Components of solutions: Solvent- the thing doing the dissolving (greater quantity) Solute - the thing being dissolved (lesser quantity) Types of solutions- gas-gas ex: oxygen in nitrogen gas-liquid ex: carbon dioxide in soda liquid-gas ex: water in air liquid-liquid ex: alcohol in water liquid-solid ex: mercury in silver and tin (dental amalgam) solid-liquid ex: sugar in water solid-solid ex: copper in nickel (alloys)

Type: 

Type If the particles in a liquid are so large that they settle out unless the mixture is constantly stirred or agitated, the mixture is called a suspension. If left undisturbed, the particles in a suspension will collect on the bottom of the jar. Particles over 1000nm in diameter form suspensions and can be separated by passing the mixture through a filter. Types of Mixtures- Suspensions

Types of Mixtures- Colloids: 

Types of Mixtures- Colloids Particles that are intermediate in size between those in solutions and suspensions from mixtures known as colloidal dispersions or simply, colloids. After large soil particles settle out of muddy water, the water is often still cloudy because colloidal particles remain dispersed in the water. If the cloudy mixture is poured through a filter, the colloidal particles will pass through and the mixture will remain cloudy . Colloids exhibit the Tyndall Effect. This phenomenon occurs when light is scattered by colloidal particles dispersed in a transparent medium. The jar on the left is a colloid and the jar on the right is a true solution.

Types of Mixtures Overview: 

Types of Mixtures Overview Solutions Colloids Suspensions Homogenous Heterogeneous Heterogeneous Particle size: Small, .01-1nm, can be atoms, ions, molecules Particle size: medium, 1-1000nm, dispersed, can be aggregates or large molecules Particle size: Large, over 1000nm, suspended, can be large particles or aggregates Do not separate upon standing Do not separate upon standing Particles settle out Cannot be separated by filtration Cannot be separated by filtration Can be separated by filtration Do not scatter light Scatters light (Tyndall effect) May scatter light , but are not transparent

Solutes: Electrolytes vs. Non-electrolytes: 

Solutes: Electrolytes vs. Non-electrolytes Substances that dissolve in water are classified according to whether they yield molecules or ions in solution. When ionic compounds dissolve in water, the positive and negative ions separate from each other and are surrounded by water molecules. The solute ions are free to move, making it possible for an electric current to pass through the solution. Covalent compounds do not yield ions in solution and are therefore classified as non-electrolytes.

13.2: The Solution Process: 

13.2: The Solution Process All of the following will increase the rate of dissolution (dissolving): Increasing surface area Agitating the solution Heating the solvent

Solubility: 

Solubility For every combination of solvent with a solid solute at a given temperature, there is a limit to the amount of solute that can be dissolved. Solution equilibrium, the physical state in which the opposing processes of dissolution and crystallization of a solute occur at equal rates .

Saturated vs. Unsaturated Solutions: 

Saturated vs. Unsaturated Solutions A solution that contains the maximum amount of dissolved solute is described as a saturated solution. How can we tell when a solution is saturated?

Supersaturated Solutions: 

Supersaturated Solutions A supersaturated solution is a solution that contains more dissolved solute than a saturated solution contains under the same conditions. Supersaturated solutions are produced by forcing more solute into solution by heating or sometimes, evaporation. The difference between a supersaturated and saturated solution is the amount of solute dissolved .

Solute-Solvent Interactions: 

Solute-Solvent Interactions LIKE DISSOLVES LIKE!!!!! This is a very useful rule for predicting whether one substance will dissolve in another. What makes substances similar? The type of bond! Polar solutes will dissolve in polar solvents Non-polar solutes will dissolve in non-polar solvents

Polar Solvents: 

Polar Solvents The polarity of water molecules plays an important role in the formation of ionic compounds in water. The charged ends of water molecules attract the ions in ionic compounds and surround them to keep them separated from the other ions in the solution. This process is called hydration . Other examples of polar solvents are ethanol, methanol and ammonia.

Non-polar Solvents: 

Non-polar solvents are typically oil based and will not dissolve ionic compounds. The non-polar solvent molecules do not attract the ions of an ionic crystal strong enough to overcome the forces holding the crystal together. Non-polar Solvents

Miscible or Immiscible?: 

Miscible or Immiscible? Remember the rule, “ Like Dissolves Like ”? When a liquid is totally dissolved by another liquid, it is said to be miscible . You will not be able to distinguish one liquid from another When one liquid is not dissolved by the other liquid, it is said to be immiscible. A clear distinction between the two liquids will be apparent.

Effects of Pressure on Solubility: 

Effects of Pressure on Solubility Changes in pressure have very little effect on the solubility of liquids or solids in liquid solvents. However, increases in pressure increase the solubility of a gas in liquid .

Effects of Temperature on Solubility: 

Effects of Temperature on Solubility First, let’s consider gas solubility . Increasing temperature decreases gas solubility. But with solids, the greater kinetic energy of the solvent generally allows for a faster rate of dissolution. Solubility Curve of Common Gases Solubility Curve of Various Solids

Solubility Curves: 

Solubility Curves Solubility curves tell us the mass of solute that will dissolve in 100 grams or 100 Liters of water Points that fall along the line represent a saturated solution. Points that fall above the line represent a supersaturated solution. Points that fall below the line represent an unsaturated solution.

Reading Solubility Curves: 

Reading Solubility Curves X axis- Temperature Y axis- Grams of solute dissolved in 100 g of water How much Lead (II) nitrate will dissolve at 30 o C? 67 grams How much Potassium chloride would I need to make a super saturated solution at 80 o C? More than 52 grams What type of solution would exist at 60o C and with 40 grams of Calcium Chloride dissolved? An unsaturated solution .