solutions. colligative property property that depends on the concentration of solute particles,...
TRANSCRIPT
![Page 1: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/1.jpg)
Solutions
![Page 2: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/2.jpg)
Colligative PropertyColligative Property
property that depends on the concentration of solute particles, not their identity
![Page 3: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/3.jpg)
Freezing Point DepressionFreezing Point Depression (tf) f.p. of a solution is lower than f.p. of the pure
solvent
Boiling Point ElevationBoiling Point Elevation (tb) b.p. of a solution is higher than b.p. of the
pure solvent
![Page 4: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/4.jpg)
View Flash animation.
Freezing Point Depression
![Page 5: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/5.jpg)
Solute particles weaken IMF in the solvent.
Boiling Point Elevation
![Page 6: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/6.jpg)
Applicationssalting icy roadsmaking ice creamantifreeze
cars (-64°C to 136°C) fish & insects
![Page 7: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/7.jpg)
t: change in temperature (°C)k: constant based on the solvent (°C·kg/mol)m:molality (m)n: # of particles
t = k · m · n
![Page 8: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/8.jpg)
# of Particles# of Particles
Nonelectrolytes (covalent) remain intact when dissolved 1 particle
Electrolytes (ionic) dissociate into ions when dissolved 2 or more particles
![Page 9: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/9.jpg)
At what temperature will a solution that is composed of 0.73 moles of glucose in 225 g of phenol boil?
m = 3.2mn = 1tb = kb · m · n
WORK:
m = 0.73mol ÷ 0.225kg
GIVEN:b.p. = ?tb = ?
kb = 3.60°C·kg/moltb = (3.60°C·kg/mol)(3.2m)(1)
tb = 12°C
b.p. = 181.8°C + 12°C
b.p. = 194°C
![Page 10: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/10.jpg)
Find the freezing point of a saturated solution of NaCl containing 28 g NaCl in 100. mL water.
m = 4.8m
n = 2
tf = kf · m · n
WORK:
m = 0.48mol ÷ 0.100kg
GIVEN:
f.p. = ?
tf = ?
kf = 1.86°C·kg/mol
tf = (1.86°C·kg/mol)(4.8m)(2)
tf = 18°C
f.p. = 0.00°C - 18°C
f.p. = -18°C
![Page 11: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/11.jpg)
Percent Solutions If both solute & solvent are liquids
Percent by volume (% v/v) = volume of solute × 100% solution volume
If a solid is dissolved in a liquidPercent (mass/volume) (%(m/v)) = mass of solute (g)
× 100%solution volume (mL)
Must be the same unit: mL or L
Must be this unit
![Page 12: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/12.jpg)
Example 1What is the percent by volume of ethanol
(C2H6O) or ethyl alcohol, in the final solution when 85 mL of ethanol is diluted to a volume of 250 mL with water?
Volume of solute = 85 mLVolume of solution = 250 mL
% (v/v) = 85 mL ethanol × 100% 250 mL solution
= 34% ethanol
% (v/v) = volume of solute × 100% volume of solution
![Page 13: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/13.jpg)
Example 2How many grams of glucose (C6H12O6)
would you need to prepare 2.0 L of 2.8% glucose (m/v) solution?
Solution volume = 2.0 L → change to mLPercent by mass = 2.8%
Percent (mass/volume) (%(m/v) = mass of solute (g) × 100%solution volume (mL)
2.8% = mass of solute (g) × 100% 2,000 mL
2.0L
100% 100%
0.028 = X 2,000 mL
X = 56 g of solute
1L1000mL= 2,000 mL
![Page 14: Solutions. Colligative Property property that depends on the concentration of solute particles, not their identity](https://reader031.vdocuments.mx/reader031/viewer/2022020111/56649f1d5503460f94c34a40/html5/thumbnails/14.jpg)
1. What is the concentration, in percent (m/v), of a solution with 75g K2SO4 in 1500mL of solution?
2. A bottle of hydrogen peroxide antiseptic is labeled 3.0% (v/v). How many mL H2O2 are in a 400.0 mL bottle of this solution?
3. Calculate the grams of solute required to make 250 mL of 0.10% MgSO4 (m/v).
Percent Solution ProblemsYou do not have to write the problem. You MUST show your work.