Sunday, September 29, 2013

Issue 32: Chemistry: Solutions (Hoyle's Freshman Honor Chem Class)

Topics:
Solutions:
How to determine which substance is more soluble:


Solute-stuff being dissolved
Solvent-stuff in which the solute is being dissolved
Soluble-solute will dissolve in the solvent to a significant extent(not quantitative)
Solubility depends on the amount of solvent and on the temperature
Typically substances are more soluble at a higher temperature (gases are exception)
Unsaturated solution-when the maximum amount of solute able to be dissolved has not been dissolved yet
Saturated Solution-maximum amount of solute has been dissolved for a given temp
Supersaturated- when the amount of salt added is less than the amount that is not dissolved
Equilibrium is when the amount of solute being dissolved is the same as the amount coming out of the solution
Solubility if there is a constant volume and temperature, the increase of pressure will result in proportional increase in solubility.
Pressure has no effect on the solubility of solids
Unsaturated solution-more solute can be dissolved in the solvent
Supersaturated solution-there is more solute dissolved than can possibly be dissolved into the solvent
It is possible to test whether a solution is saturated, unsaturated, or supersaturated by:
1) adding more of the solute. If the solute dissolves, the solution was unsaturated. If the solute sinks to the bottom, the solution was saturated. If the substance crystallizes, the solute was an agitator, thus the substance was supersaturated.
2) distillation. Water is separated from the solute. Both of them would be weighted, and use the information on their masses to determine whether it’s unsaturated, saturated, or supersaturated according to the reference table.
Dilute: there is more of the solvent per solute
Concentrated: opposite of that ^^
Gas laws:
Combined Gas Law: P1V1/T1=P2V2/T2
Boyle’s Law: PV=Constant= P2V2
This is an inverse Proportion meaning as one goes up, the other goes down.
Concentration and Temperature are constants in boyle’s law
Charles Law
Volume (L)/Temperature (K) = Constant
*Temperature must be Kelvin
This is a Direct Proportion meaning if Temperature goes up or down, Volume does the same in order to keep the pressure constant.
Avogadro's Law
At the same temperature and pressure, all gases will have the same volume if the # of molecules are the same.(mol=n)
Ideal gas law: PV=nRT
R= 0.0821 atm * liters/mol * kelvin



Ideal Gas aka Kinetic Molecular Theory
1. Gas molecules have no volume or IMFs.Volume is the space between the molecules
2. No IMF’s
3. Molecules move in random straight line motion
4. Collisions are elastic


Other things to remember:
1 ml of water=1 cm3 of water
22.4 L of gas=1 mole of gas at STP



Websites/Resources:





Created by Hoyle's Chem Class of 2012-2013
(Freshman Honor Chem)

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