1. Solutions
Homogeneous mixture
Solute
Solvent

2. Solution Formation Rate
Factors affecting it…
Temperature—think about dissovling sugar in tea
Agitation—again think about the tea
Particle size—granulated sugar vs. powdered sugar?

3. Henry’s Law
The solubility (C) of a gas in a liquid is directly proportional to the pressure above the liquid
C1 = C2
P1 P2
Think about carbonated beverages

4. Henry’s Law Problem
At 20°C and 1.00atm, the solubility of oxygen gas in water is g/L. What will the solubility be if the pressure is increased to 1.75atm?
Answer: g/L

5. Concentration
Qualitative descriptions do not give amounts of solute in solution.
Concentrated—lots of solute
Dilute—not much solute
Note: no quantities are provided

6. Concentration A few types… Molarity Mass percent Mass/volume percent
Volume/volume percent
Mole fraction
Molality

7. Molarity Represented by M—always uppercase M = #moles of solute
#liters of solution
Units will be mol/L, or you may write it as M
A 2M solution is described as “two molar”

8. Mass Percent Represented as m/m% m/m% = mass of solute x 100
mass of solution
Mass units must be the same for the solute and the solution
Unit-less

9. Mass/volume Percent Represented as m/v% m/v% = #g of solute x 100
#mL of solution
Units are specific
g/mL

10. Volume/volume Percent
Represented by (v/v)%
(v/v)% = volume of solute x 100
volume of solution
Volume units must be the same for the solute and the solution
Unit-less

11. Mole Fraction Represented by Greek letter, chi, χ
χsolute = #mol of solute
#mol of solution
χsolvent = #mol of solvent
Unit-less
Sum will
be one

12. Molality Represented by m—always lowercase m = #moles of solute
#kg of solvent
Units will be mol/kg, or you may write it as m
A 2m solution is described as “two molal”

13. Dilutions
I don’t usually stock every concentration of every acid that I need…so I start with the most concentrated form and make whatever molarity (the most common measurement of concentration) I need.
(M1)(V1) = (M2)(V2)

14. Dilutions
The rule of thumb is if you’re making an acid dilution in a beaker, always add the acid to water…so if something splashes, it will be the water!

15. Practice #1
How many grams of sodium hydroxide are required to make 250mL of a 0.25M solution?
Answer: 2.50g NaOH

16. Practice #2
How many grams of water are present in a 5.00%(m/m) solution containing 0.875g of calcium acetate?
Answer: g H2O

17. Practice #3
How many grams of acetic acid are present in 4.50L of a 5.00%(m/v) solution?
Answer: 225g HC2H3O2

18. Practice #4
A 95% (v/v) solution of ethanol in double-distilled water is used to clean surfaces in a laboratory setting. If you have 500mL of the solution, how many of those mL are water?
Answer: 25mL H2O

19. Practice #5
10.0g of calcium acetate are added to 100g of water. What are the mole fractions of both the solute and the solvent?
Answer: χcalcium acetate =
χwater = 0.989

20. Practice #6
10.0g of calcium acetate is added to 100g of water. What is the molality of this solution?
Answer: mol/kg or m

21. Practice #7
If I need to make 250mL of 6M sulfuric acid, and all I have in my cabinet is full strength, 18M sulfuric acid, describe how I make the dilution.
Answer: measure 83.3mL of 18M H2SO4 and
pour into the 250-mL volumetric flask. Fill
the flask to the etched line with water, cork it,
and agitate it.

22. A Doozie Problem
A solution is prepared by mixing 1.00g of ethanol, CH3CH2OH, with 100.0g of water to give a final volume of 101.0mL of solution. Calculate the molarity, mass percent, mass/volume percent, molality, mole fraction of the ethanol, and mole fraction of the water.

23. A Doozie’s Answers… molarity = 0.215M or 0.215mol/L
mass percent = 0.990%
mass/volume percent = 0.990(g/mL)%
molality = 0.217m or 0.217mol/kg
mole fractionethanol =
mole fractionwater = 0.996