SCH 3U: UNIT 6 : CONCENTRATION
OF SOLUTIONS / ACIDS & BASES
1) CONCENTRATION OF SOLUTIONS.
A. Intro
- What makes up a solution? Sketch the parts of a solution below. Relate this to solubility.
B. Concentration as a MASS / VOLUME PERCENT
m/V% = mass of solute / vol of solution * 100
page 302
e.g 1. You have a part-time job in a pharmacy and make a drug solution by adding 2.00 mL of distilled
water to 4.00 g of the powdered drug. The final volume of the solution is 3.00 mL. a) What concentration
will you write on the container (in g/100 mL solution)? B) What is the percent (m/v) of the solution?
C. MASS / MASS PERCENT
m/m% = mass of solute / mass of sol’n * 100
page 306
e.g 2. In the winter, calcium chloride can be used to melt ice on the sidewalks around the school. You took
a sample of slush to analyze how much calcium chloride was being added to our sidewalks. The sample
had a mass of 23.47 g and when the liquid was evaporated, the residue had a mass of 4.58 g. What was the
mass percent of calcium chloride in the slush? How many g of calcium chloride is present in 100 g slush?
D. VOLUME / VOLUME PERCENT
V/V% = volume of solute / vol of sol’n * 100
page 309
e.g. 3. Rubbing alcohol is commonly used as an antiseptic for small cuts. It is sold as a 70% (v/v) solution
of isopropyl alcohol in water. What volume of isopropyl alcohol is used to make 500 mL of rubbing
alcohol?
E. PARTS PER MILLION
ppm = mass of solute / mass of sol’n * 106
page 311
Sample Problem (pg. 311) – Parts per Billion in Peanut Butter
Try: #s 1,2,3,4 on assignment 6:1 – questions from the text
F. MOLAR CONCENTRATION page 313
C
= # moles/# L
or
[sol’n] = mass / molar mass/# L
G. USING MOLAR CONCENTRATION TO FIND MASS TO MAKE SOL’NS
mass = [sol’n] * molar mass * # L
page 313
H. DILUTIONS - # moles stay the same  volume changes
# moles(stock)
= # moles (diluted)
page 320
or [stock sol’n] * # L stock = [diluted sol’n] * # L dil
I. MIXTURES- # moles increases and total volume changes
[mixture] = total# moles / total # L
or [mixture] = [sol’n A] * # LA + [sol’n B] * # LB / (# LA # LB)
Try #s 5-14 on assignment 6:1
* 2: Stoichiometry in solution chemistry
A. Review: concentration of individual ions in a solution
*look at sample problems on pg 351& 353
9.3 page 348