How to make super kool aid or extreme jello Kool Aid Jello Chapter How to make super kool aid or extreme jello

Kool Aid drinks are solutions Solutions are homogenous mixtures of two or more pure substances in a single phase Contains a solvent and solute Solvent: dissolving medium (water) Solute: dissolved substance(salt) Particle sizes are the smallest Will not separate while standing Do not filter Do not scatter light Colligative properties are affected

Solutions

Muddy water is a Suspension Suspensions are heterogeneous mixtures that have the largest particles of all mixtures Will separate upon standing Can be filtered Do scatter light Colligative properties are unaffected Examples: Muddy water, Cu Lab.

Suspensions

Milk/Gelatins are Colloids Colloids are homogeneous mixtures that are medium in size. Particles remain dispersed in liquid due to random particle motion of surrounding molecules. Will separate very slowly or not at all Will not filter Will scatter light Colligative properties are unaffected.

What is this scattering light?

Tyndall Effect Light bounces off objects it cannot pass through, is scattered by objects, or passes right through objects. The scattering of light as it passes through a transparent medium is called the Tyndall Effect.

When focused light is shined on a homogeneous solution the light will not be scattered; it will pass right through. When focuses light is shined on a colloid the light will be scattered and no longer as focused.

What are they? Oil and vinegar salad dressing? Gelatin? Starch in water? Smoke in air? Salt in water? Clay in water? Food coloring in water?

Carbon dioxide in water? Steam in air? Table sugar in water? Milk? Bleach? Ammonia? Tea?

More on Solutions The M’s of it all

Concentration Different solutions can have different concentrations by dissolving more or less solute in a given amount of solvent Concentrations is scaled on molality and molarity

Molarity Molarity(M) is defined as the number of moles of solute per liter of solution M=moles of solute/liters of solution

Molality Molality(m) is defined at the number of moles of solute divided by the number of kilograms of solvent M = moles of solute/kg of solvent

Solubility Solubility is the chemical process in which chemicals are able to dissolve each other (able to mix well) The ability to mixed is determined by the types of bonds holding the chemical together. “like dissolve like”

Miscible Alcohol and water mix quite readily due to the stronger forces of attraction between the solvent and solute. Both water and alcohol are polar bonds and therefore can dissolve each other. Miscible is the ability to dissolve each other due to similar bonds

Immiscible Immiscible chemicals have opposite forces of attraction and therefore DO NOT MIX Oil and water Mystic sand and water

Colligative Properties of Solutions Not freezing when cold or boiling when hot!

Colligative Properties Some of the properties of solutions do not depend on the amount and type of solute present in solution. Ie food coloring doesn’t affect the boiling point of water (much) Properties that depend on the concentration of solute particles but not on their identity are called Colligative properties.

Electrolyte and non Electrolyte Electrolytes are substances that dissolve in water to give a solution that conducts an electric current Sports drinks and salt water Ionic compounds are usually strong electrolytes because they separate completely in water Covalent compounds can be strong, weak or non electroyltes

Non-electrolytes: a liquid or solid substance that does not allow the flow of an electric current, either in solution or in its pure state, such as water or sucrose. Nonvolatile substance is one that has little tendency to become a gas under existing conditions

Freezing point depression The freezing point of a 1 molal solution of any nonelectrolyte solute in water is found to be 1.86 degrees lower than the freezing point of water. Thus 1 mole of solute in 1 kg of water will equal -1.86 degree C

If you had 2 moles of solute in 1 kg of water the freezing point would be -3.72 degree C. This is 1.86 X 2 This 1.86 degree C/m is known as molal freezing point constant (Kf) Molal Freezing point constant is the freezing point depression of the solvent in a 1 molal solution of a nonvolatile, non electrolyte solute.

Kf for substances Each solvent has its own characteristic molal freezing point constant. Kf is most accurate at 1 atm. Kf for water is -1.86, for Ether is -1.79 and Acetic Acid -3.90

The freezing point depression, ∆tf, is the difference between the freezing points of the pure solvent and a solution of a non electrolyte in that solvent, and it is directly proportional to the molal concentration of the solution. ∆tf=Kf*m

Did you know? Some animals are able to survive freezing temperatures by producing natural antifreezes, substances that lower the freezing point of a liquid. In many freeze-tolerant insects, the antifreezes are alcohols and sugars. Examples are box turtles, painted turtles and garter snakes, sugar maples and white spruce.

Sugar Maple Taking a sugar substance from a tree can be used to create maple syrup The maple syrup aqueous solution boils at 219 degree F That is 7 degree higher than water. Why?

Boiling point elevation The boiling point of a liquid is the temperature at which the vapor pressure of the liquid is equal to the prevailing atmospheric pressure. Vapor pressures of solutions containing nonvolatile solute is lower than the vapor pressure of the pure solvent.

This means that more heat will be required to raise the vapor pressure of the solution. Thus, the boiling point of a solution is higher than the boiling point of the pure substance. The molal boiling point constant, Kb, is the boiling point elevation of the solvent in a 1 molal solution of a nonvolatile, non electrolyte solute.

Boiling point elevation Boiling point elevation, ∆tb, is the difference between the boiling points of the pure solvent and a nonelectrolyte solution of that solvent, and it is directly proportional to the molal concentration of the solution. ∆tb=Kb*m

What about Electrolytes? Electrolytes break apart into ions. Each ion has an effect on boiling point and freezing points. If a solution has more or less ions it will change the boiling points and melting points even more.

Ions ∆tb or f=Kb or f*m*n m=molality n = number of ions Example NaCl = Na+ and Cl- = 2 ions=2 n MgCl2= Mg+ and 2 Cl- =3 ions =3 n Fe2(SO4)3=2 Fe+3 and 3 SO4-2 = 5 ions or 5 n

Example What is the new freezing point of 200 mL of water (Kf = -1.86 oC) if195 g of sucrose (C12H22O11) are added to it?

195 g sucrose = .570 moles 342 g .570 moles = 2.85 molal .200 Kg Now we can plug into ∆tf=Kf*m

∆tf=(-1.86oC) * (2.85 molal) ∆tf= -5.3010C This means the water will freeze 5.301oC below its freezing point.

∆tb or f=Kb or f*m*n Same as other formula, just adding n. NaCl, K2SO4, AlCl3, Al2O3.