Solution and Colligative Properties Flashcards
Matter exists in two types
pure substances
mixtures
have fixed composition such as elements and compounds
pure substances
have variable composition
mixtures
Two types of mixture:
homogenous
heterogenous
have a single phase and are same in appearance throughout
homogenous mixture
mixture that have two or more distinct phases
heterogeneous mixture
homogenous mixtures that consists of solute and solvent
solution
substance that is dissolved
solute
dissolving agent
solvent
Solution may be classified according to the state of matter (solid, liquid, or gas) of the solvent and the solute such as:
liquid-liquid soln
liquid-solid soln
liquid-gas soln
solid-solid soln
solid-gas soln
gas-gas soln
contains less amount of solvent
concentrated soln
contains more solvent
dilute solution
maximum amount of solute dissolved by a given amount of solvent at a definite temperature
solubility
Temperature dependent
solubility
contains less solute and completely dissolves in a given amount of solvent, at a particular temperature
unsaturated
the solvent contains the maximum amount of solute at a particular temperature
saturated
contains the maximum amount of solute at a higher temperature
supersaturated
The solubility of a particular solute in a given solvent is affected by several factors which includes the following
particle size
temperature
nature of solute and solvent
pressure
smaller particle size has larger surface area, thus, there is more points of interactions between the solute and solvent molecules. T
Therefore, smaller particle size favors a _____ rate of dissolution
faster
in general, a higher temperature (increases/decreases) the solubility of solid solute in liquid. The opposite is true for gases which becomes (more/less) soluble in liquid as temperature increases
increases, less
solubility follows the rule βlike ____likeβ.
dissolves
Polar solutes dissolve in polar/nonpolar solvent while nonpolar solute dissolves in nonpolar/polar solvent
polar
nonpolar
this applies only to gaseous solute in liquid. An increase in pressure ____the rate of the solubility of gas
increases
as the temperature increases, solubility _____ (in most cases) except in gases (more heat, (more/less) gas dissolves)
increases
less
as the pressure _____ , solubility _____
increases
the _____ the surface area, the faster it dissolves
larger
quantitative way of such description
concentration units
common concentration units
% by mass
% by volume
% by mass-volume
molarity
molality
mole fraction
parts per unit (ppm, ppb, ppt)
formula by % by mass
mass of solute / mass of solution * 100
formula of % by volume
volume of solute / volume of solution * 100
formula of % by mass volume
mass of solute (g) / volume of solution (mL) *100
formula of density
mass/volume
formula of mass
(density)(volume)
formula of volume
mass/density
Acetone, C3H6O, is the main ingredient in nail polish remover. A solution is made up by adding 35.0 mL of acetone (d= 0.790 g/mL) to 50.0 mL of ethyl alcohol, C2H6O (d=0.789 g/mL). Assuming volumes are additive, calculate the following:
the mass percent of acetone in the solution
=41.2%
Acetone, C3H6O, is the main ingredient in nail polish remover. A solution is made up by adding 35.0 mL of acetone (d= 0.790 g/mL) to 50.0 mL of ethyl alcohol, C2H6O (d=0.789 g/mL). Assuming volumes are additive, calculate the following:
b. the volume percent of ethyl alcohol in the solution
41.2%
formula for molarity
moles solute / volume of soln (L)
formula for molality
moles solute / mass (kg) solvent
mole fraction formula
number of moles solute / total number of moles soln
Calculate the molarity, molality, and mole fraction of NH3 for a solution of 30.0g of NH3 in 70.0g of water. The density of the solution is 0.982 g/mL.
molarity =17.3π
molality = 25.1π
mole fraction = 0.312
Reagent grade nitric acid is 71.0% nitric acid by mass and has a density of 1.418 g/mL. calculate the molarity, molality, and mole fraction of nitric acid in the solution.
molarity = 16.0 π π»ππ3
molality = 39.0 π π»ππ3
mole fraction = 0.412
ppm units
mg/L or mg/kg
ppb units
ΞΌg/L or ΞΌg/kg
ppt units
ng/L or ng/kg
A 2.6g sample of plant tissue was analyzed and found to contain 3.6ΞΌg zinc, what is the concentration of zinc in the plant sample in ppm and ppb
ppm = 1.4 ppm Zn
ppb = 1385 ppb Zn
process of preparing a less concentrated solution from a more concentrated one
dilution
to carry out proper dilution, it is important to calculate the needed amount of concentrate for dilution into specific concentration unit,
give the formula that describes the unit of a concentrated solution and its volume to a less concentrated solution and its volume
πΆ1π1= πΆ2π2
Describe how you would prepare 500.0 mL 0.150 M NaOH solution from stock solution of 2.50 M NaOH.
30.0 ππΏ
stepwise dilution process using a certain dilution factor
serial dilution
HCl comes in 10mL bottles of 1M concentration. You serially dilute it 3 times, diluting the solution by Β½ each time. What is the concentration of the HCl at the end.
first dilution = 0.5 M
second dilution = 0.25 M
third dilution = 0.125 M
are those dependent only on the amount of solute and not only on its nature
colligative properties
Four specific colligative properties
freezing point depression
boiling point elevation
vapor pressure lowering
osmotic pressure
whenever this is placed in car radiators, boiling point elevation is applied
coolant
When a solute is dissolved in the solvent the freezing point of the resulting solution is ___ than the freezing point of the pure solvent.
lower
the boiling point of the solution is ___ compared to that of the pure solvent.
higher
Formula for freezing point depression
π₯ππ= πππ
π₯ππ= πππ
Kf = ?
m = ?
kf = freezing point depression constant
m = molality
formula for boiling point depression
π₯ππ= πππ
π₯ππ= πππ
ΞTb = ?
Kb = ?
m = ?
ΞTb = boiling point elevation
Kb = boiling point elevation constant
m = molality
Calculate the boiling point and freezing point of a solution containing 478 g of ethylene glycol in 3202 g of water. Molar mass of ethylene glycol is 62.07 g/mole. Use data from table 3.1.
Kf = 1.86ππΆ/π
Kb = 0.51ππΆ/m
freezing point of water = 0.0^oC
boiling point of water = 101.2^oC
π₯ππ= -4.46^oC
ΞTb = 100.0oC
movement of solute molecules from an area of higher concentration to an area of lower concentration
diffusion
is the diffusion of solvent across a membrane, the movement of the solvent molecules from a region of lower solute concentration to a region of higher solute concentration
osmosis
process of separating molecules in solution by the difference in their rates of diffusion through a semipermeable membrane
dialysis
can be used to determine the molar mass of certain compounds
osmotic pressure
A 202-mL benzene solution containing 2.47g of an organic polymer has an osmotic pressure of 8.63 mmHg at 21oC. calculate the molar mass of the polymer.
1 atm = 760mmHg
C + 273 = Kelvin
2.59π₯104 π/ππππ
when a solute is added the vapor pressure above the solution becomes lower compared to that of a pure solvent
vapor pressure lowering
formula for vapor pressure lowering
π₯π= π2π1π
Complete the following table for aqueous solutions of potassium hydroxide. Show complete solution. Molar mass KOH = 56.11 g/mole; H2O = 18.02g/mole.
refer to the ppt slide
grade yourself accordingly
Complete the following table for aqueous solution of potassium hydroxide. Show complete solution. Molar mass KOH = 56.11 g/mole ; H2O = 18.02 g/mole
refer to ppt slide
grade yourself accordingly
Complete the following table for aqueous solutions of potassium hydroxide. Show complete solution. Molar mass of KOH = 56.11 g/mole; H2O = 18.02 g/mole
refer to ppt slide
grade yourself accordingly
A solution is prepared by dissolving 396g of sucrose (C12H22O11) in 624g of water. What is the vapor pressure of this solution at 30oC (the vapor pressure of water is 31.8 mmHg at 30oC)
- Mass of sucrose = 396g
- Mass of water = 624g
- Vapor pressure of water at 30oC = 31.8mmHg
1.03πππ»π