Chem Phys Exam 2 Flashcards
Molecular interactions often occur in _____________
Solutions
Solution
- Homogenous mixture in which one substance is dispersed in another as individual atoms or molecules
- liquid solution is transparent
Clear Solution
- When you have a solution and you have a solute it disperses to individual atoms or molecules
- When this happens, molecules are so small they do NOT bend light, so solution is clear
Cloudy Liquid
- Large particle that refract light
- Particles stick together- make cloudy liquid
- NOT considered a solution
Sodium Chloride
Ion-Ion interaction
NaCl——> Na+ Cl-
NaCl in solution
- Ion- diploe interaction
- Separates into anion and water molecules=partial positive
- Proton portion=partial positive charge
Acid
Compound in which hydrogen ions are associated with an anion
Disassociates in solution:
1. Hydrogen ion (H+)
2. Anion
Mixtures that are NOT Solutions
- Cloudy liquid (solutions are clear)
- gasoline and water
- oil and vinegar
- Diprivan (propofol)
- Maalox
- NPH insulin (mixture and solution)
Gasoline and Water
-Most important of polar ends=do NOT mix
-oil is less dense, floats to top and water is on bottom
-Not enough interactions between these two for them to come
Together, react, and stay together
Concentrations and Dilutions
- Molarity: best way to capture measurement
- Molality
- Normality
- Equivalents
- Osmolarity
Concentrated Solution
- Color will give you idea about how concentrated a solution is
- Molecules are not bound together, but they are closer to each other
- More chemical reactions occur in concentrated solutions than in dilute solutions
Dilute Solution
- Less chemical reactions occurring in this solution
- Molecules or atoms are farther apart
Mole
- Amount of a substance equal to its formula weight in grams
- How we quantify all of the molecules and atoms we cannot see
Example of Atomic Weight: 1 Mole of atoms
Hydrogen= Atomic weight 1 1gram (1 mole of atoms)
Carbon= Atomic weight 12: 12 grams (1 mole of atoms)
Nitrogen=atomic weight 14 14 grams (1 mole of atoms)
Molecular weight of H2 & 1 mole of H2
Molecular weight= 2
1 mole of H2= 2 grams
Molecular weight of N2 & 1 mole of N2
Molecular weight of N2= 28
1 mole of N2= 28 grams
Mole
Weight in grams of a substance equal to its:
- Formula Weight
- Molecular Weight
- Gram molecular weight
- Atomic Mass Units
Avogadro’s Number
- Number of atoms (for an element) or molecules (for a compound) in a mole
- 1 mole contains 6.02 X 10^23
- This number does NOT change
Molarity
Means of expressing the concentration of a certain species in solution in units of moles per liter
Molarity- How to calculate 1 Molar Solution
- 1 Molar Solution (1 M)
- Weight out solute as precisely as possible (molecular weight in grams)
- Add enough water to make 1 liter as precisely as possible
- want to make 1.000 M solution
Molarity example: NaHCO3
- Molecular weight: (23+1+12+16x3)
- 84 gram/liter=1 M
- 84 mg/liter= 1mM - 1milimolar (1,000X less)
- Usually talk about milimolar in chemistry
Calculations to Know: Molarity
Molarity=Moles per liter
Calculations to know: Moles
Moles= weight/ weight per mole
Calculations to know: Weight
Weight= moles X weight per mole
Calculations to know: Concentration
Concentration=moles/volume
Scientific Notation
Useful for expressing numbers that are very large and very small
Exponents: 10^0, 10^1, 10^2
10^0= 1 (zero zeros) 10^1= 10 (1 zero) 10^2= 100 (2 zeros)
To determine the exponent
- Count number of zeros after the 1
- Count number of places decimal point has been displaced from 1
Determine 10,000= 10^?
Count number of zeros=4
10,000= 10^4
Exponents of numbers
-exponents of numbers
Negative Exponents:
.1
.01
.001
.1= 10 ^-1= 1/10 .01= 10^-2= 1/100 .001= 10^-3= 1/1000
Kilo (k)
Thousand
10^3= 1,000
Milli (m)
One- thousandth
10^-3= 1/1000
Mega (M)
Million
10^6= 1,000,000
Micro
One-millionth
10^-6= 1/1,000,000
Giga
Billion
10^9
Tera
10^12
Trillion
Deci
10^-1= 1/10
Centi
10^-2= 1/100
Nano
10^-9
Pico
10^-12
Femto
10^-15
Atto
10^-18
F degree is _________ than C degree
Small
Difference is factor of 100/180= 5/9
32 degree F= ___________ C
0 degree Celsius
Conversion from F to C
C= (F-32) X 5/9
Conversion from C to F
F= C X 9/5 + 32
Conversion from C to Kelvin
K= C + 273
0 degree Celsius= _______ K
- 15 K
180 C=__________ K
372.15 K
Pressure:
1 atm=________ mmHG
1 atm= _______ torr
1 atm= 760 mmHG, 760 torr
1 mmHG= _______ torr
1 torr
760 torr= _______ atm
1 atm
1 atm= ________ psi
1 atm= ________ ft water
1 atm= ________ inches Hg
1 atm= ________ kPa
- 7 PSI
- 9 ft water
- 92 inches HG
- 325 kPa
Weight: 1 kg= ____ pounds
2.2 pounds
Weight: 1 pound=______ grams
454 grams
Volume: 1 liter=_______ ml
1000
1 ml= ____ cc
1 cc
1000ml=________ kg
1 kg
1 liter= ____ quarts
1.06 quarts
1 quart= ________ ml
946 ml
20 drops= ________ cc
1 TB= _______ ml
1 ounce= ________ ml
1 cc
15 ml
29.6 ml
Distance: 1 cm= \_\_\_\_\_ inches 1 inch= \_\_\_\_\_\_ cm 1 kilometer= \_\_\_\_\_\_ miles 1 mile= \_\_\_\_\_\_\_\_ kilometers
1 cm= .39 inches
1 inch= 2.54 cm
1 kilometer= .62 miles
1 mile= 1.61 kilometers
Don’t round off a calculated Quantity When all of the Numbers in your equation are _________________
- Precise
- If you can measure out 2.19 grams with your measuring device then do that
- Know when it’s appropriate to be precise (weighing out NaCl) and when it’s okay to not be (baking a cake)
When solving for Molarity what units should your answer be in?
- Moles/liter= M
- if asked for a concentrated in mM, then you must convert from M to mM
Molality
-Means of expressing the concentration of a certain species in solution in terms of moles per KG of water
-1 Molal solution: weight out MW in grams
-add exactly 1kg (1 Liter) of water.
Total volume will be greater than 1L
Normality
-means of expressing the concentration of an acid in terms of hydrogen ion equivalents
HCl= _________ normality
1 molar= 1 normality
Only one Hydrogen ion
H3PO4= __________ Normality
1 molar= 3 normality
3 Hydrogen ions
Equivalents
-Means of expressing the concentration of a species in terms of the number of ions released
Equivalents:
100 mM of NaCl:
1 liter= ___________ mEq Cl-
1 liter= 100 mEq of Cl-
Because there is only one Cl- ion
Equivalents:
100 mM of FeCl3
1 liter= _________ mEq of Cl-
1 Liter= 300 mEq of Cl-
Because there is 3 Cl- ions
Osmolarity
-Means of expressing the overall number of particles in solution
Without regard to their identity
-Represents the total concentration of all species
Osmolarity Example:
NaCL: 1 mM= _________ mOsm/liter
1mM= 2 mosm/liter
Na+ & Cl= 2 separate ions
Osmolarity Example:
1 mM of MgSO4= ________ mOsm/liter
1 mM of MgSO4= 2 mOsm/liter
Mg 2+ & SO4-2
1:1
- Basic unit on which others are based
- 1 gram/ml
1%
1 gram/100 ml (w/v)
1 ml/100 ml (v/v)
Mg %
- mg/DL
- mg/100 ml
Definition of a Solution
- Homogenous mixture in which one substance is dispersed in another as individual atoms or molecules
- Liquid Solution:
1. Transparent
2. Passes through filter
3. Does not settle upon standing
Solvent
-Substance in which a solute dissolve to form a solution
Solute
-Substance that dissolves in a solvent to form a solution
Saturated Solution
- solution in which solvent is unable to hold any more solute
- solvent may be in equilibrium with an excess of undissolved solute
Suspension
- Finely divided solid particles dispersed in a liquid
- Particles will settle upon standing under the influence of gravity
- Must shake or mix before using
- Particle size > 1 um trapped by filter
Tyndall Effect
- to distinguish solution from suspension which contains excess undissolved solute
- particles not in solution scatter light
- solvent will not be transparent to beam of light
La Chatelier’s Principle
-if a system at equilibrium is perturbed, the system moves to counteract the effects of the change
Crystalloid
- Soltuion: particles are distributed as individual molecules
- Particles are small enough to diffuse through a semi-permeable membrane
- Particles are not trapped by a filter
Examples of Crystalloids
- LR
- NS
- D5W
Colloid
- Finely divided particles dispersed in a liquid (or gas)
- Particles are too small to settle under the influence of gravity
Colloid
- Particles are too large to diffuse through semi-permeable membrane
- Particles not trapped by a filter
- Particle size is 2-1,000 nm
Examples of colloids
- milk
- dextran
- hespan
- albumin
- fog
- smoke
Emulsion
- Particles or globules of one liquid dispersed in another liquid
- Liquids are immiscible
- Layers may separate on standing
- May contain emulsifier to prevent separation
Micelle
- Hydrophilic head
- Aqueous solution
- Hydrophobic tail
Examples of emulsions:
- Diprivian
- TPN
- Mayonnaise
- Butter
- Detergent on dirty clothes
Soap
Ionic end= polar and hydrophilic
Hydro carbon Chain= non polar and hydrophobic
Cleaning action*
Examples of suspensions:
- NPH insulin
- Maalox
- Blood
- Oral Antibiotics
Density
- mass per volume
- gram/ml
Density of Water
- maximum at 3.98 degree C
- by definition, 1 gram/cc
- 1 gram/ml
- 1 kg/liter
Specific Gravity
- Weight of a substance compared to the weight of the same volume of a reference compound
- Reference compound is usually water at its maximum density
- Equivalent to density of substance in gram/ml without units
- Ratio that has no units
Ethanol:
Density= 0.789 grams/ml
Spec gravity=_____________?
Spec gravity= .789 (NO UNIT)
Accuracy
Does the measurement give you the “right” answer
Think of darts and Bulls eye
Reliability
- Reproductibility
- extent to which a measurement gives the same answer every time
Can a measurement be reliable but not accurate?
Yes
Example: tape measure if it’s been stretched
Example: non calibrated thermometer
Precision
- Extent to which a measurement can distinguish between 2 closely spaced values
- Directly related to a number of significant digits in a measurement
- Number of significant digits in value should be appropriate for the context: Measurment device, use of measurement
Validity
-Extent to which a measurement provides a true indication of the parameter of interest
-A measurement can be accurate, reliable and precise but NOT valid
Example: IQ test as a measure of intelligence
Questionable Validity
- blood pH as a measure of acid/base status
- pulse oximetry to monitor organ perfusion
- pupillary size as an indicator of ICP
- arterial line to monitor fluid status
Gas
- No definite shape or volume, conforms to container, fills container, flows and is easily compressible
- gases that do NOT react chemically= homogenous mixture
- Molcules high kinetic energy, large distances, do not interact with each other or container
- Ideal gas= no intermolecular forces
Liquids
- Definite Volume
- Conforms to shape of container
- Flows, not compressible
- Molecular distance small, medium kinetic energy, inter-molecular forces hold condensed state but allow molecules to slide against each other
Solids
- Definite volume, definite shape
- Molecules are densely packed, minimal kinetic energy, ordered structure
Common Gases
- O2
- N2
- CO2
- CO
Force
F= pressure/area
Volume cylinder
V=area base X height
Area of a circle
PiR(2)
Volume of a cube
Side(3)
Volume of a circle
4/3 Pi r (3)
Temperature Conversions:
Boiling H20= F____=C______=K_________
Freezing H20= F______=C______=K________
O degree K=_________C=________F
Boiling H20= 212F= 100C= 373.15K
Freezing H20= 32F=0C-273.15K
O K= -273 C= -524 F
1 atm=_____mmHg=_______ PSI=_____ kPa
1 atm= 760 mmHG= 14.7PSI=101 kPa
Measuring Pressure
- Atmospheric pressure exists
- Gauge pressure is pressure within vessel (tank) ABOVE atmospheric pressure
- Bourdon spring gauge (Pressure causes coiled copper to straighten) 02 tank gauges
Avogadro’s Number and Hypothesis
#= 6.02 X 10(23) the number of molecules in one mole of a substance Hypothesis= one mole of gas at standard temperature (O degree C or 273.15K) and pressure (1 atm/1bar or 100 kPa) (STP) occupies a volume of 22.4 liters -at equal temperature and pressure, equal volumes of gas contain equal numbers of gas particles
How much volume is occupied by 2 moles of oxygen?
2 moles X 22.4L/mole= 44.8 liters of oxygen
How much volume is occupied by a 2 mole of 50:50 mixture of O2/N2O?
2 moles X 22.4L= 44.8 Liters of O2/N2O
Charles’ Law
-Volume of a gas is proportional to its absolute temperature as long as the pressure and amount of gas are held constant
VI/T1=V2/T2
NOTE: no p in this equation because pressure is constant
Temperature must be in Kelvin
Kelvin= C + 273.15
Charles’ Law
-If you have a certain molar amount of gas and increase its temperature, the volume of space occupied by that gas will increase and vice versa.
Boyles’ Law
-Volume of a gas is proportional to its pressure as long as the TEMPERATURE is held constant
P1V1=P2V2
Note: No T because temperature is constant
-decreased volume= increased pressure
-increased volume=decreased pressure
-Units of pressure and volume do not matter as long as they match on both sides
Boyles’ Law:
What happens when we contract our diaphragm?
- Contract our diaphragm, the pressure inside the lungs drops below atmospheric pressure and air flows into our lungs
- When we release our diaphragm, pressure inside the lungs increase and volume of gas flows out of the lungs
Gay-Lussac’s Law
-Pressure is proportional to absolute temperature (Kelvin) if volume is constant
-As temperature increases, pressure increases and vice versa
P1/T1=P2/T2
NOTE: no V because volume is constant
The “Universal” or “Ideal” Gas Law
PV=nRT
Pressure (atm) X volume (L)= n (number of moles per gas) X R (universal gas constant (8.314 J/mol K)X T (temperature in K)
Kinetic Molecular Theory: first 3?
- Ideal gases consist of a large number of tiny particles
- Gas particles are in constant, random motion
- Gas particles are small compared to the distance b/t them
Kinetic Molecular Theory: 4-6?
- Volume of particle sis negligible
- Gas particles do not react chemically with the other container or each other
- No forces of attraction or repulsion b/t gas molecules or the container
Kinetic Molecular Theory 7-9?
- Collisions b/t particles and container are perfectly elastic (no energy is lost)
- Pressure is caused by collisions b/t particles and container walls
- Average kinetic energy of a collection of gas particles depends on their absolute temperature and NOTHING else
At STP (O degree C) and 1 atm (760mmhg) 1 mole of an ideal case will occupy how much space?
- 22.4 liters of space
At room temp (68 degree, 1 mole of ideal gas occupies 24L of space)
Dalton’s Law of Partial Pressures
-The total pressure in a mixture of gases is equal to the sum of the partial pressures of the individual gases in the mixture
P (total)= PO2 + PCO2 + PN2O
The partial pressure of a gas is equal to the (Fi% X atmospheric pressure)
Need to know Fi% of the gas to make this law work
What is the partial pressure of O2 in room air?
- RA FiO2 is 21%
- Atmospheric pressure is 760
.21 X 760= 159.6 mmHG
NOTE: pO2 and PCO2 is the partial pressure of Oxygen and CO2 in the blood.
Composition of Dry Room Air
Nitrogen: 78%= 593 mmHG
Oxygen: 21%= 159 mmHG
Argon: 1%= 8 mmHG
CO2: .03%= .2 mmHG
Anesthetic partial pressures: Iso, Sevo, Des
- 1% Isoflurance= 1 volume ISO/ 100 volume of carrier gas, Partial Pressure= 240 mmhg
- 2% Sevoflurance= 2 volumes SEVO/ 100 volume of carrier gas, Partial Pressure= 170 mmhg
- 6% Des= 6 cc des fluorane/100 cc oxygen/air, 669 mmhg
Mole Fraction
- Mole fraction of each component is the number of moles compared to the total number of moles of gas present
- P1+P2= (N1+N2) RT/v
The partial pressure of each gas is directly related to the # of moles of the gas
Law of LaPlace-Cylinders
T= P X R (T= wall tension, P= pressure, R= radius of cylinder)
- As cylinder expands, the radius increases. As radius increases, wall tension increases.
- As blood vessel dilates from increased fluid, wall tension in the vessel increases. Greater likelihood of rupture
- Capillaries withstand high pressure better than large vessels especially veins because their radius is smaller and therefore the wall tension is lower
Law of LaPlace- Spheres (alveoli)
T=Pr/2, or 2T= Pr, or P=2T/r
Alevoli without surfactant: P= 2T/r
-when R decreases, pressure in the alveoli increases if wall tension is the same
-When pressure increases in small alveoli (small R), P in small alveoli is higher than larger alveoli and air moves from small to large, and small alveoli collapse
-Result= atelectasis & ARDS. Premature infants born without surfactant
Law of LaPlace- Spheres- Alveoli with surfactant
P=2T/r
- surfactant allows for the surface tension to increase as radius increases
- maintaining T keeps pressure within the alveoli the same
- when P1=P2, gas does not move from A1 to A2
Henry’s Law
- amount of gas that dissolves in a liquid is directly proportional to the partial pressure of the gas in the gas phase over/around that liquid.
- Blood is a liquid. O2, Co2, and Anesthetic agents=gas
Oxygen Carrying Capacity Equation
CaO2= (1.34 X Hgb X SaO2) + 0.003 (PaO2)
-Answer is in ml/DL?
Note:
PAO2= alveolar oxygen partial pressure= 6X FiO2
PaO2= arterial oxygen partial pressure= 5X FiO2
Graham’s Law
-Rate of diffusion through an office of a gas is inversely proportional to the square root of the molecular weight
R=1/ (square root of MW)
-Smaller molecules diffuse through membranes faster, larger slower
-Large molecules have higher molecular weight.
-This relates to second gas effect w/ Nitrous Oxide: rapid uptake of smaller molecule leaves higher concentration of large molecules that are left behind).
-this relates to diffusion hypoxia which can occur w/ N2O: reverse of
Second gas effect. Smaller molecules rush out and reduce concentration of the larger molecules.
