Chapter 8 Flashcards
Mol /kg of solvent
Molality
moles of solute/Liter of solution
Molarity
Percentt by weight
allows you to measure out a volume of medicine in a syringe, and calculate the mass of the drug
Percent by volume
not on the test
Equivalents (Eq)
Analogous to mole
Equivalent definition
one Eq of a substance contains one mole of chemical reactivity
Ex One Eq of an acid can deliver
one mole of H+ ions
1 Eq/mol of H+
Ex calcium has
2 Eq /mol
1 mol is expressed in
Eq/L
1 mol of Ca is
1 mol / 2 eq
Parts per million
can be used as away to define concentration
PPM calculates as
grams of solute per one million grams of solution
What is the concentration of a solution in parts per million,
0.02/1000
Solubility
the mass of solute that will dissolve in a given amount of solvent
NACL is
very soluble in water
O2 is
not very soluble in water
A saturation solution contains
the maximum amount of solute as defined by its solubility
Supersaturated solution
contains a concentration greater than its solubility limit. The solute precipitates out
Example of supersaturation (2)
- excessive amount of ca2 in the blood precipitate out as calcium crystals forming kidney stones
- Sodium acetate crystals precipitate out of supersaturated solution
Factors affecting solubility: Increases pressure
Increase pressure = increase gas solubility in a liquid
Factors affecting solubility: Increasing Temperature
Increase solids & Liquids solubilities in other liquids
Factors affecting solubility:Increasing temperature, ______gas solubility in a liquid
Decrease solubility in a liquid
Henry’s Law
give relationship between pressure and solubiliy
S=
S= K(h) P(gas) S= Solubility K(h) = Henry's constant
Henry’s law
if you double the pressure in the chamber with pure oxygen, the amount of oxygen dissolve in the water doubles to 84mg/L
Henry’s law
but if you have mix of gases, then you have to account for partial pressure. For examples, @ 2 atm in the chamber we have mix of 50% oxygen & 50% nitrogen
The henry’s law constant for oxygen in water 0.042g/L/atm at 25C. What is the solubilityis mg /L of O2 in pure water at 740 torr room air ?
Fist convert torr to atm = 0.974 atm oxygen is 21% : (0.21) (0.974) = 0.204 atm now plug in number S= (0.042)(0.204)= 0.0086g/L Concert to mg/L Final : 8.6mg/L
Heats of solution
forming solution can be endothermic (solution gets cold) exothermic ( solution gets hot) depending on the intermolecular forces and particle interaction between the solute particles themselves and the solvent particles.
Lattice energy
the attraction of solute particles for each other
Solvation energy
the attraction of solute particles and solvent molecules
When a solution form if lattice> solvation
endothermic (because it takes energy out of the solvent to break apart the lattice)
When a solution form if lattice < solvation
exothermic , because energy is released into the solvent
Mole fraction of a solute is equal to
the moles of solute in a sample divided by the total number of moles of substances in the sample
Xi =
mol (I) / mol (I) + mol (solvent)
Osmosis Capital PI =
MRT
M molarity
R is the idea gas constant
T (temp in Kelvin)
Osmosis definition
Tonicity definition
movement of water across a semipermeable membrane from an area of greater concentration to an area of lesser concentration
- Tonicity describes the concentration of 2 solutions relative to each other.
What osmotic pressure would an aqueous solution of 1 mol of glucose exert against pure water at 298K?
(1mol/L) (0.0821 L/atm/mol/k) (298)=
24.5 atm
Osmosis and tonicity
net movement of H2o into and out of RBC
What is a solution?
Ex?
homogeneous mix of solutes in a solvent
Ex: Salt in water
Homogenous means there are no
visible phase boundaries
MISCIBLE refers to
liquids that mix evenly, forming homogenous solution that do not separate
Miscible or Immiscible–>Water and methylene
Immiscible
Miscible or Immiscible–>Acetone and water
Miscible
Solution vs colloid vs suspension depends on
Particle size.
Particles size less than 10^-7cm
True Solution
Particles size between 10^-7cm to 10^-5cm
Colloid Solution
Particle size greater than 10^-5cm
Suspensions
Appearance of a solution is ________ and appearance of colloid is ________
transparent; cloudy
Particle size of a solution is ____________ and particle size of colloid is __________
Molecule size ; variable , larger than molecule
Effect of light : Tyndall effect on solution?
None
Effect of light : Tyndall effect on colloid?
Light dispersed in a ray
Solutes dissolves in
Solvents
Solutes and solvents, both can be
liquid, solids or gases
Example of liquid solute in liquid solvent
Alcohol: 70% isopropanol
30% water
Example of solid solute in liquid solvent
0.9% NaCl
Example of gas solute in liquid solvent
CO2 in beer
Example of solid solute in solid solvent
Stainless Steel alloys
What is the definition of molarity
Mole of solute per liter of solution(mol/L)
What are Colligative Properties?
Physical properties of a solution that are affected only by the CONCENTRATION of SOLUTE particle, NOT BY THE identity of the solute itself.
Example of the application of colligative properties
By adding salt to water you change the colligative properties of the water: Vapor pressure Decreased Boiling point Increased Freezing point Decreased Osmotic pressure increased
Vapor pressure _________ as more solute is added
Decreases
Addition of solute and vapor pressure
inverse proportional relationship
Salts lowers
Freezing point of water
Salt raises
boiling point of water
osmotic pressure of blood
If you dissolved 1 mol of glucose in enough water to give you a total 1L of solution, you would have________and not ________
1 molar solution of glucose: 1 L of water
If you started with 1L of water and then added 1 mol of glucose,
the final solution would be more than 1L
Calculate the molarity of a D5W solution prepared by dissolving 1 g of C6H12O6 in enough water to give a total volume of 20ml?
1g/180g = 0.0055555 Mol = 0.0055555/ 0.02L M = 0.28
Relationship of molarity with temperature?
why?
Inverse proportional relationship–> as temperature increases, molarity decreases
Volume of the solvent EXPANDS at higher temperature
MoLAlity
mol of solute / kg of solvent (not liter)
If you dissolved 1 mol of NaCl in 1 kg of water, you would have
1 molal solution of NaCl
% w/v
Defined as gram of solute per 100ml of solution
Grams of solute / ml of solution x100%
What is the concentration of a solution prepared by dissolving 25g of glucose in enough water to give a total volume of 500ml?
25/500 x 100= 5%
How many liters of D5W are required to deliver 100g of glucose?
2000ml
what is the percent by weight concentration of glucose in a solution prepared by dissolving 25g of glucose in 475 g of water?
25/500 x 100 =5%
When expressing Eq of electrolyte cations in the body, the number of Eqs in a mole is equal to
the charge on the cation.
Blood work says 40mEq/L , calculate mole per Liter?
First convert mEq to Eq
than 1mol = 2 Eq
Parts per million (ppm)
- can be use a way to define concentration
- concentrate as gram of solute per one million g of solution
ppm = grams of solute/grams of solution x1,000,000
What is the concentration of a solution, in pars per million. If 0.02g of NaCL is dissolved 1000 g of solution
0.02g/1000g x 1000000 = 20ppm
What is the PPM concentration of chromium in the blood if we have a level of 2.5mcg per 100ml? (blood density =1.06g/ml)
0.024ppm
What osmotic pressure would an aqueous solution of 1 mol of glucose exert against pure water at 298K?
24.5atm
