Test3 Flashcards
Characteristics of a Solid
1) Molecules arranged in a regular pattern
2) Molecules held firm in place but can vibrate within a limited area.
3) Molecules are touching
4) Molecules held in place by intermolecular forces
5) Not compressible
6) Have a definite volume and shape
Characteristics of a Liquid
1) Molecules are touching but flow easily around one another
2) Intermolecular forces are weak but are kept from flying apart by attractive forces
3) Have definite volume but no shape - liquids assume the shape of their containers
4) Not compressible
Characteristics of a Gas
1) Molecules fly in all directions at great speeds
2) Molecules are so far apart that the attractive forces btw them are insignificant
3) Have no volume or shape
4) Expand to fill a container
5) Compressible
Name the following changes of states:
1) Liquid to gas
2) Gas to liquid
3) Gas to solid
4) Solid to gas
5) Solid to liquid
6) Liquid to solid
1) Liquid to gas - Vaporization
2) Gas to liquid - Condensation
3) Gas to solid - Deposition
4) Solid to gas - Sublimination
5) Solid to liquid - Melting
6) Liquid to solid - Freezing
What is heat of fusion
The amount of energy needed to melt solid into a liquid
What is heat of vaporization
The amount of energy needed vaporize a liquid into a gas
Difference btw heat and temperature
Heat is the amount of energy flowing into an object
Describe the process of melting
As heat energy is added to system, vibration btw particles become greater until that movement overcomes the intermolecular forces holding the molecules together, causing dissociation into a liquid state.
Describe the process of vaporization
A heat energy is added to system, the movement of the molecules continue to increase overwhelming the forces and particles begin to escape the liquid surface, vaporizing into a gas.
Characteristics of intermolecular forces
1) Determine how molecules interact with one another
2) Are electrostatic in nature
3) Are based on electron organization of the particles
4) Atoms tend to gain, lose or share electrons in order to achieve a total of 8 valence electrons (like noble gases)
5) The closer an element is to a noble gas, the more reactive is is (electronegative)
3 Types of intermolecular Forces
1) Dipole:Dipole (i.e. acetone) - polar molecule, boiling point 56C, liquid at room temp
2) Hydrogen (i.e. water) - Polar molecule, strongest type of dipole bond, boiling point 100C, liquid at room temp.
3) London Dispersion Forces (i.e. CH4) - Non-polar molecule, weakest type of intermolecular bond, boiling point -164C, gas at room temp
Lewis Structure
1) Describe chemical bonds using valence electrons
2) Lines = shared pair of electrons
3) Dots = lone pair of electrons
Ionic Bond
1) One atom donates an electron to another (i.e. Na+ and Cl- = NaCl)
2) Strongest type of bond
3) Usually a metal donating and electron to a non-metal
Covalent bond
1) Atoms share electrons (i.e. H+ and O– = H2O
2) Not as strong as ionic
Describe a Polar-Covalent Bond
When shared electrons spend more time around the more electronegative atom (i.e. H2O)
What is a Hydrogen Bond
1) When a H atom is bonded directly to O, N, or F.
2) H is left as a focused point of partial positive charge (i.e. H20 and NH3).
Describe Surface Tension
When molecule are attracted to each other on a surface . i.e. water molecules causes side-to-side and downward attraction forces, but no balancing attractions from above the liquid. The unbalanced force creates a “skin”.
Describe surface tension in the lungs and how surfactant comes in to play
- Thin film of fluid lining the lungs (held together by surface tension) could cause the walls of the lungs to stick together and collapse
- Surfactant reduces the surface tension so this doesn’t happen
Where is inhaled anesthetics absorbed in the lungs?
In the alveoli
Inhaled anesthetics come in what form? What form is it changed to, in order to be delivered to the PT??
- Come in Liquid form
- Changed into a vapor via vaporizers
Define Vapor Pressure
When molecules of a liquid escape into a gas phase, they collide with the walls of the container, exerting a force on the walls called vapor pressure
Describe Volatility
1) Volatility is the tendency of a liquid to change to a gas
2) Higher volatility = higher evaporation (I.E. ROH vs H20)
3) Higher volatility = higher vapor pressure
How does temperature affect vapor pressure
An increase in temp. causes an increase in vapor pressure
Simplify the Clausius-Capeyron equation
Ln(P) = (ΔHvap/R) * (I/T) + C
same as
logP = A + B/T
The Clausius-Capeyron equation is used to calculate what?
The vapor pressure of a liquid
If Enflurane, A = 7.967 torr, B= -1687 torr*K
What is the vapor pressure of enflurane at 25C
- logP = 7.967 + (-1678/298K)
- logP = 2.34 (now take antilog to solve for P)
- On your calculator antilog = 10^x
- Antilog (2.34) - 10 ^2.34 = 217torr or 217 mmHg)
Find mole fraction of Enflurane if we run O2 through a vaporizer at 25C. The pressure of the mixture is 750 torr.
Xenflurane = vapor-of-enflurane/total-pressure
Xenflurane = 217/750 or 0.29
Define Boiling Point
Boiling point is the temperature at which the vapor pressure is equal to the ambient pressure (normally one atmosphere).
How does boiling point relate to the pressure of a liquid
- Boiling point of a liquid will increase if the pressure on the liquid is increased
- i.e. Water normally boils into steam at 100C, but in a sealed pressurized autoclave, the boiling point increases to 120C or more.
What is a phase Diagram
A diagram that shows the combined effects of temp. and pressure on the state of matter
What is the triple point of water
0.01C - temp at which water can exist in all 3 states (gas, liquid, solid)
Define a Solution
A homogenous mix of solutes in a solvent
Define Homogenous in regards to a mixture
When there are no visible phase boundaries i.e. salt water.
Define Miscible
Referes to liquids that mix evenly, forming a homogenous solution the do not separate i.e. water and acetone
Solution vs. Colloid vs. Suspension particle sizes
- Depends on particle size
1) Solution - particle size < 10^-7cm
2) Colloidal - particle size btw 10^-7 and 10^-5cm
3) Suspensions - particle size > 10^-5cm
Colloid vs. Suspension appearance and light effect
1) Colloid - transparent and no Tyndall effect
2) Suspension - cloudy and light dispersed in a ray
Types of Solutions
1) Liquid in liquid - i.e. 70% isopropanol and 30% water
2) Solid in liquid - i.e. 0.9% NaCl
3) Gas in liquid - i.e. CO2 in beer
4) Solid in Solid - stainless steel alloys
Define Colligative properties
Physical properties of a solution that are affected only by the concentration of solute particles, not the identity of the solute itself. i.e. by adding salt to water, you change the colligative properties of the water
Examples of Colligative Properties
1) Vapor Pressure
2) Boiling Point
3) Freezing Point
4) Osmotic Pressure
How does salt affect the freezing point and boiling point of water
1) Salt lowers freezing point of water
2) Salt raises boiling point of water
How does salt affect the osmotic pressure of blood
Salt raises osmotic pressure of blood
Define Molarity
Molarity (M) is moles of solute per liter of solution (give relationship of moles to volume)
mol/L (moles of solute/Liters of Solution)
Calculate the molarity of a D5W solution prepared by dissolving 1 g of glucose (C6H12O6) in enough water to give a total volume of 20 ml.
12C x 6 = 72
12H x 1 = 12
6O x 18 = 96»_space;> 72+12+96 = 180g/1mol.»_space;»>
180g/1mol = 1g/xmols»_space;» x = 5.56 x 10^-3 mols»_space;»>
5.56 x 10^-3 mols/.02L = .278M
How does temperature affect molarity? why?
- As temperature of a solution increases, Molarity decreases.
- This is because the volume of the solvent expands at higher temps.
Define Molality
Moles of solute (m) per kilogram of solvent (gives relationship of moles to weight: mol/kg
Molality = Moles of solute/Kg of solvent
Calculate the molality of a solution prepared by dissolving 1 g of glucose in 20 g of water.
5.56 x 10^-3mols/.02kg = .278m
Percent by Weight to Volume (% w/v)
- Allows you to measure out a volume of medicine in a syringe and calculate the mass of the drug.
- Defined as grams of solute per 100 ml solution
% w/v = (grams of solute over mL of solution) x 100%
What is the concentration of a solution prepared by dissolving 25g of glucose in enough water to give a total volume of 500 ml?
= 25g glucose x 100%
500 ml of solution
or 5%
How many liters of D5W are required to deliver 100g of glucose?
- Since D5W is 5% (w/v) glucose
100g/x = .05»_space;> x = 2000mL
What is the percent by weight conc. Of glucose in a solution prepared by dissolving 25 g glucose in 475 g of water?
25gglu/25gglu + 475gH2O = .05 or 5%
Equivalents (Eq)
- One Eq of a substance contains one mole of chemical reactivity.
- one Eq of an acid can deliver one mole of H+ ions.
- one Eq of an oxidizing agent can accept one mole of electrons.
- i.e. Na+ cation has 1 Eq/mol
Ca2+ cation has 2
Eq/mol
Pt.s blood work says calcium ion content is 40 mEq/L.
Calculate moles per Liter?
2eq/1mol = 48meq(.04eq)/xmols >>>> x = .02mols >>>> Since 40g cal = 1mol then 40g/1mol = xg/.02mols >>>> x = .8g or 800mg
Define Parts per million (ppm)
- used as a way to define concentration.
- Calculated as grams of solute per one million grams of solution. (grams per million)
ppm = (grams of solute/grams of solution) x 1,000,000
What is the concentration of a solution, in parts per million, if 0.02 gram of NaCl is dissolved in 1000 grams of solution?
(.02g/1000g) x 1,000,000 = 20 ppm
What is the ppm concentration of chromium in the blood if we have a level of 2.5 μg per 100 ml? (Blood density = 1.06g/ml)
(2.5 x 10^-6g of Cr/106g of blood) x 1,000,000 = .024ppm
Define Solubility
The mass of solute that will dissolve in a given amount of solvent.
Solubility of NaCl in water
- NaCl has a solubility of 36 g per 100 ml of water at 25C
- NaCl is very soluble in water.
Solubility of O2 in water
O2 has a solubility of 42mg per L of water at 25C.
- O2 is not very soluble in water.
Define a Saturated Solution
A Saturated Solution contains the maximum amount of solute as defined by its solubility.
Define a Supersaturated Solution, give an example
Contains a concentration greater than its solubility limit. The Solute precipitates out.
i.e. excessive amounts of Ca++ in the blood precipitate out as calcium crystals forming kidney stones.
How does pressure and temperature affect solubility?
1) ↑ Pressure = ↑ gas solubility in a liquid
2) ↑ Temperature = ↑ solids & liquids solubilities in other liquids
3) ↑ Temperature = ↓ gas solubility in a liquid
Henry’s Law
Gives relationship between pressure and solubility
S = kH Pgas
- S = solubility
- kH = Henry’s constant (specific for each solute, solvent & temp.)
- Pgas = Partial pressure of the gas
Solubility of Oxygen in water
- The solubility of oxygen is: S = 42 mg/L
- kH for oxygen in water is 0.042 g/L/atm
- If you have 1 L of water in a chamber of pure 100% oxygen @ 1 atm,
42 mg of oxygen will dissolve into the Liter of water.
The Henry’s Law constant for oxygen in water is 0.042 g/L/atm at 25C. What is the solubility (in mg/L) of O2 in pure water at 740 torr room air?
1atm/760torr = xatm/740torr»_space; x = .974atm
Since O2 is 21%»_space;»
(0.21)(9.74atm) = 0.204atmPgas; Since S = kHPgas; then
»> S = .042x.204 = .0086g/L or 8.6mg/L
Lattice energy vs Salvation energy
1) Lattice energy - is the attraction of solute particles for each other.
2) Solvation energy - the attraction of solute particles and solvent molecules.
Endothermic vs. Exothermic process when a solution forms
1) If Lattice energy > Solvation energy = endothermic. Because it takes energy out of the solvent to break apart the lattice
2) If Lattice energy < Solvation energy = exothermic Because energy is released into the solvent
Define Mole Fraction
The mole fraction of a solute ( X i ) is equal to the moles of solute in a sample divided by the total number of moles of substances in the sample.
X i = mol I/mol total
Formula for Osmotic Pressure
Π = MRT Π is the osmotic pressure in atm M is molarity R is the ideal gas constant (using 0.0821 as Π is reported in atm.s) T is temperature in Kelvin
Define Osmosis
the movement of water across a semipermeable membrane from an area of greater concentration to an area of lesser concentration.
Define Tonicity
the concentration of two solutions in relation to each other
What does ph represent?
1) pH = potential hydrogen
2) pH is the concentration of hydrogen ions (H+)
pH range of blood that causes death?
< 6.8 or > 8.0
Define an Acid and a Base
- An Acid is a molecule the can donate a H+
- A base is a molecule that can accept a H+
Explain Bronsted’s Theory
1) Defines an Acid as a proton donor, or H+ donor
2) Defines a Base as a proton acceptor
What is a Conjugate Acid and a Conjugate base?
1) Conjugate Acid - When a base accepts a Proton, it is converted into its *Conjugate Acid (i.e. NH3 + H+ –> *NH4+)
2) Conjugate Base - When an Acid donates a proton, what remains is called the *Conjugate Base (i.e. HCL –> H+ + *Cl-)
Strong Acid vs. a Weak Acid
1) Strong Acids dissociate completely into a solution (i.e. HCl and NaOH)
2) Weak Acids dissociate only partially in a solution (i.e. Lactic acid and carbonic acid)
How do you find the pH of a solution given the concentration of H+
pH = -log[H+]
How do you calculate H+ concentration, given the the pH
[H+] = 10^-pH
Calculate the [H+] for a pH of 7.3 using the shortcut for nEq/L
[H+] = 10^(9-7.3) = 50.1nEq/L
Calculate the pH of a solution when the [H+] is 1 x 10^-3
pH = -log(1 x 10^-3M) = 3
What do ABG values indicate?
Indicates how well a patient is exchanging gases in the lungs and how well the body is maintaining normal pH.
What are the normal values for the following:
1) pH
2) PaCO2
3) HCO3
4) PaO2
1) pH - 7.35 to 7.45
2) PaCO2 - 35 to 45 mmHg
3) HCO3 - 22 to 26 mEq/L
4) PaO2 - 80 to 100 mmHg
ABG Interpretation
1) Step 1 - Check PaO2 (80 t0 100); if < 80 = hypoxic, if > 100 = hyperoxygenated
2) Step 2 - Check pH (7.4); if 7.35 to 7.45 = compensated acidosis or alkalosis; if < 7.35 = uncompensated acidosis, if > 7.45 = uncompensated alkalosis
3) Step 3 - Check PaCO2 (35 to 45) alkaloid or acidotic range? Correlate with pH and if both pH and CO2 match, cause is respiratory
Step 4 - Check HCO3 (22 to 26) acidotic or alkaloid range? Correlate with pH and if both pH and HCO3 match, cause = metabolic.
*If all 3 (pH, CO2, and HCO3) match, cause = combined
Interpret the following ABG values:
1) PaO2 - 90
2) pH - 7.52
3) PaCO2 - 43
4) HCO3 - 30
Uncompensated metabolic alkalosis
Interpret the following ABG values:
1) PaO2 - 90
2) pH - 7.52
3) PaCO2 - 49
4) HCO3 - 30
Partially compensated metabolic alkalosis
Interpret the following ABG values:
1) PaO2 - 90
2) pH - 7.52
3) PaCO2 - 29
4) HCO3 - 30
Combined alkalosis - because both CO2 and HCO3 are contributing to the pH alkalosis
Describe the following Imbalances:
1) Compensated
2) Uncompensated
3) Partially Compensated
4) Combined
1) Compensated - pH in range w/ both #s off
2) Uncompensated - pH out of range w/ one off & one normal
3) Partially Compensated - pH out of range w/ both #s off
4) Combined - pH out of range w/ both #s contributing
Interpret the following ABG values:
1) PaO2 - 75
2) pH - 7.36
3) PaCO2 - 50
4) HCO3 - 30
Compensated Respiratory acidosis
Interpret the following ABG values:
1) PaO2 - 89
2) pH - 7.41
3) PaCO2 - 52
4) HCO3 - 31
Compensated metabolic alkalosis
Interpret the following ABG values:
1) PaO2 - 90
2) pH - 7.36
3) PaCO2 - 29
4) HCO3 - 18
Compensated metabolic acidosis
Interpret the following ABG values:
1) PaO2 - 93
2) pH - 7.44
3) PaCO2 - 27
4) HCO3 - 16
Compensated respiratory alkalosis
How does the body maintain pH?
Buffer Systems:
1) Prevent major changes in pH by removing or releasing hydrogen (H+) ions
2) Act chemically to change strong acids into weaker acids or to bind acids to neutralize their effects
What is the first line of defense against pH shift
Chemical Buffer System - Includes bicarbonate system, phosphate system, and protein buffer system
What is the second line of defense against pH shift
Physiological Buffer System - Includes Respiratory mechanism (CO2 excretion) and Renal mechanism (H+ excretion)
Explain the Carbonic Acid Buffer System
Carbonic acid (H2CO3) - Bicarbonate buffer system – most important ECF buffer against non-carbonic acid changes
Explain the Protein Buffer System
- It includes Hgb and is the largest buffer in the body; important ICF and ECF buffer.
- Hemoglobin buffer system – primary buffer against carbonic acid changes (via carbaminohemoglobin)
Explain the Phosphate Buffer System
important intracellular and urinary buffer:
1) H+ + HPO42- ↔ H2PO4-
2) OH- + H2PO4- ↔ H2O + HPO42-
Kassirer-Bleich equation
1) [H+] = 24 x PCO2/HCO3 ¯
2) allows calculation of [H+] and pH if PCO2 and HCO3 are known
Metabolic Acidosis/Alkalosis = ?
disturbances of bicarbonate
Respiratory Acidosis/Alkalosis = ?
disturbances of PaCO2
Why does a normal [H+] of 40 nEq/L corresponds to a pH of 7.40.
Because the pH is a negative logarithm of the [H+]
How are changes in pH related to changes in [H+]
They are inversely related (i.e. decrease in pH is associated with an increase in [H+]).
What happens when a primary acid-base disturbance alters one component of the PCO2/[HCO3- ] ratio?
The compensatory response alters the other component in the same direction to keep the PCO2/[HCO3- ] ratio constant.
End-Point PCO2/[HCO3-] Ratio Primary and compensatory change for respiratory acidosis
1) Primary change - PCO2 up
2) Compensatory change - HCO3 up
End-Point PCO2/[HCO3-] Ratio Primary and compensatory change for respiratory alkalosis
1) Primary change - PCO2 down
2) Compensatory change - HCO3 down
End-Point PCO2/[HCO3-] Ratio Primary and compensatory change for metabolic acidosis
1) Primary change - HCO3 down
2) Compensatory change - PCO2 down
End-Point PCO2/[HCO3-] Ratio Primary and compensatory change for metabolic alkalosis
1) Primary change - HCO3 up
2) Compensatory change - PCO2 up
Given the following ABG values:
- pH - 7.30
- PaCO2 - 65
1) What is the hydrogen ion concentration?
2) What is the bicarbonate ion concentration?
3) What is the acid-base disorder?
1) H+ = 10^9-7.3 = 50.1nEq/L
2) Since [H+] = 24 x PCO2/HCO3 ¯ then [HCO3 -] = 24 x (65 / 50.1 )»_space;> [HCO3 -] = 31.1 mEq/L
3) Compensated condition - since pH is within normal range but HCO3- is high
