SOLUTIONS Chapter 12 West Valley High School General Chemistry Mr. Mata.
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Transcript of SOLUTIONS Chapter 12 West Valley High School General Chemistry Mr. Mata.
SOLUTIONSChapter 12
West Valley High SchoolGeneral Chemistry
Mr. Mata
Standard 5
Students know that temperature, pressure, and surface area affect the dissolving process.
Essential Question:
What are the components of a
solution and how do solutions,
suspensions, and colloids
differ from one another?
What is a Solution? Solution = homogeneous mixture of
two or more substances.
(solute & solvent) Solute = substance being dissolved. Solvent = substance doing the
dissolving. Homogeneous mixture = completely
dissolved & uniform solute in solvent Aqueous solution = solution in which
the solvent is water.
Parts of a Solution
Homogeneous vs. Heterogeneous
• 24-karat gold is pure gold = homogeneous
• 14-karat gold is an alloy (mixture) Au, Ag, Cu = heterogeneous• 14-karat gold is 14/24 (58.3%) gold
Solubility Terminology Soluble = substance that can be
dissolved. Insoluble = substance that cannot be
dissolved. Solubility = measure of how much
solute will dissolve in solvent. Miscible = two liquids that dissolve in
each other (ex: water & ethanol). Immiscible = two liquids that don’t
dissolve in each other (ex: H2O & oil).
Immiscible Liquids
Solubility Terminology SATURATED—contains the maximum
amount of solute. UNSATURATED—contains less solute
than a saturated solution. SUPERSATURATED—contains more
solute than it should.
Solution Saturations
Factors affecting Solubility
Stirring (agitation) increases solubility. Surface Area (particle size) smaller size
increases surface area: increases sol. Pressure (gases) increased pressure
increases gas solubility. Temperature (solids & gases).
solids: temp increase = increases solubility
gases: temp increase = decrease solubility
Solution Concentration Concentration: measure of the amount
of solute that is dissolved in a given quantity of solvent.
Dilute solution = solution that contains small amount of solute.
Concentrated solution = solution that contains a large amount of solute.
Molarity (M) = moles of solute/L of soln Units = M or moles/Liter (mol/L).
Suspensions Suspension – particles in a solvent are
so large that they settle to bottom unless agitated.
Ex: muddy water Soil particles will sink to bottom. Can be separated from heterogeneous
mixtures by filtering.
Colloids Particles are intermediate in size
between those in solutions and suspensions.
1 nanometer (nm) to 1000 nm. Cause mixture to look “cloudy”. Ex: mayonnaise Egg yolk keeps the oil droplets
dispersed.
MOLARITY
Molarity (M) = moles of solute
Liters of solution
Units in mol/L or M
A saline solution contains 0.90 g NaCl in exactly 100 mL of solution. What is the molarity of the solution?
M = moles solute Liters of solution0.90 g NaCl x 1 mol NaCl = 0.02 mol NaCl 58 g NaCl100 mL x 1 L = 0.1 L 1000 mL M = 0.02 mol = 0.2 mol/L or 0.2 M 0.1 L
M = moles solute Liters of solution
325 g CaCl2 x 1 mol CaCl2 = 2.95 mol CaCl2
110 g CaCl22500 mL x 1 L = 2.5 L 1000 mL M = 2.95 mol = 1.2 mol/L or 1.2 M 2.5 L
A solution contains 325 g CaCl2 in exactly 2500 mL of solution. What is the molarity of the solution?
How many moles of solute are present in 1.5 L of 0.24 M Na2SO4?
M = mol -> mol = ML
L
0.24 M Na2SO4 = 0.24 mol/L Na2SO4
Mol = (0.24 mol/L) (1.5L) = 0.36 mol
How many moles of solute are present in 20 L of 12 M H2SO4?
M = mol -> mol = ML
L
12 M H2SO4 = 12 mol/L H2SO4
Mol = (12 mol/L) (20L) = 240 mol
Percent SolutionsWhat is the percent by volume of ethanol in the
final solution when 85 mL of ethanol is diluted with 250 mL of water?
%v/v = volume of solute x 100
solution volume
%v/v = 85 mL ethanol x 100 =
250 mL H2O
= 34% ethanol (v/v)
Percent Solutions
What is the percent by volume of ethanol in the final solution when 300 mL of ethanol is diluted with 600 mL of water?
%v/v = volume of solute x 100
solution volume
%v/v = 300 mL ethanol x 100 =
600 mL H2O
= 50% ethanol (v/v)
Parts per Million Parts per million (ppm) Aqueous solutions: 1 ppm = 1000 ng/L
The federal limit of lead in tap water is 0.015 ppm. Express this concentration in ng/L.
0.015 ppm x 1000 ng/L = 15 ng/L
1 ppm
Parts per Million
The federal limit of mercury in tap water is 0.0002 ppm. Express this concentration in ng/L.
0.0002 ppm x 1000 ng/L = .2 ng/L
1 ppm
Chapter 12 SUTW Prompt Describe the differences between an
unsaturated, saturated, and supersaturated solution.
Complete a 10 -12 sentence paragraph using the SUTW paragraph format. Hilight using green, yellow, and pink.
Due Date: Tomorrow (start of class).