Week 1 - Basic Chemistry Review Flashcards
Compare and Contrast:
Solids, Liquids, Gases, Plasma
Solid: materials that resist changes in shape and volume
Liquid: fluid, not compressible, may change volume with changes in pressure/temp
Gases: fluid, compressible, easily change volume with changes in pressure/temp
Plasma: heated gas where electrons come loose
Describe the structure of an atom
Nucleus - central core (contains protons and neutrons) - protons determine what element it is
Electrons - orbiting particles (negatively charged) (determine the reactivity of the element)
Describe atomic structures of:
Hydrogen, Oxygen, Carbon, Nitrogen
Hydrogen (63%) - 1 valence electron
Oxygen (24.2%) - 6 valence electrons
Carbon (10.5%) - 4 valence electrons
Nitrogen (1.35%) - 5 valence electrons
“Rule of Eight” (Octet Rule)
Bonds are formed such that each atom is surrounded by a complete octet (8) of electrons (except hydrogen)
Molecules are more stable with 8 electrons in the outer shell
How much energy is required to remove an electron from the atom?
Electrons in the lowest energy level require the most energy to be removed from the atom
Electrons in the higher energy levels require less energy to be removed from the atom
What are Ionic Bonds?
Made by the attraction of electrons between atoms due to electron distribution - “opposites attract”
Atoms fill their outer shells by completely acquiring or losing electrons becoming ionized “+ or -“
Types: Ion-Ion, Ion-Dipole, Dipole-Dipole
Ex: Na loses outer electron to form cation (+) Cl gains electron to form anion (-) they attract to each other and form NaCl via ionic bond
What are Covalent Bonds?
The physical sharing of electrons between atoms
Can have single, double, or triple bonds
Stronger than ionic bonds
Ex: Carbon binding with 4 hydrogen
Saturated Hydrocarbons vs Unsaturated Hydrocarbons
Saturated: single-bonded (alkanes) carbon chains with all available carbon bonds attached to hydrogen
Unsaturated: double (alkenes) or even triple (alkynes) bonds between the carbon atoms
What are Ion-Ion Forces?
Ions of like charges repel one another and ions of unlike charges attract one another (“Opposites attract”)
Not Directional, occur anywhere along the outer shell
Lead to the formation of ionic solids at room temp - readily dissolve in water
High melting and boiling points
Ex: NaCl
What are Induced Dipole Forces?
Distribution of electrons in a nonpolar molecule can be distorted by a nearing electrical charge to induce a dipole
Weak and only effective at a short range
What are Ion-Dipole Forces?
Interaction of a polar molecule with both + and - ions
+ ions are attracted by the - end of the dipole and repelled by the + end and vice versa
Weaker than ion-ion
Requires a mixture of two or more substances: one to provide ions and another to provide polar molecules
Ex: interaction of water with dissolved ions
What are Dipole-Dipole Forces?
Attractive forces resulting from the interaction of polar molecules
Moderately strong but weaker than ion-ion
Attractions fall off more rapidly with distance than ion-ion forces
What is Hydrogen Bonding?
Special type of dipole-dipole attraction
Occurs when H+ covalently bound to a nitrogen, oxygen, or fluorine interacts with the lone pair of a second such atom nearby
Stronger than other dipole-dipole but weaker than covalent bonds
May be intermolecular or intramolecular
What are London Dispersion Forces?
A fluctuation of the electron distribution on one atom induces a corresponding temporary dipole moment on a neighboring atom – the two dipoles moments interact to give a net attractive force
Strength increases with the number of electrons in the atom (heavier atoms interact more strongly than lighter ones)
Ex: interaction with an inert gas
Intermolecular Forces of Attraction (strength of attraction related to escape of electrons)
The higher the strength of attraction is the harder it is for electrons to escape into gases thus increasing the boiling point
How does greater intramolecular forces affect surface tension, vapor pressure, boiling point, melting temp, and freezing point
Greater Intramolecular Forces Have:
- Greater surface tension
- Lower saturated vapor pressures
- Higher boiling points
- Higher melting temperatures
- Lower freezing points
Intermolecular forces related to solubility
Substances that exhibit similar types of intermolecular forces dissolve in each other
Polar molecules/Ionic compounds will be more soluble in polar solvents (dipole-dipole or ion-dipole attractions between solute and solvent)
Nonpolar molecules are soluble in nonpolar solvents (London dispersion attraction between solute and solvent)
Define: Lipophilic, Lipophobic, Hydrophobic, Hydrophilic, Aqueous, Water-soluble
Lipophilic: having affinity for lipids/fats
Lipophobic: lacking affinity for lipids/fats
Hydrophobic: lacking affinity for water
Hydrophilic: having strong affinity for water
Aqueous: pertaining to or resembling water
Water-Soluble: capable of dissolving in water
What are cell membranes permeable to and not permeable to?
Freely permeable to water, small uncharged molecules, lipid soluble compounds and hydrophobic compounds (gases)
NOT permeable to large molecules in general, large polar substances and charged substances
(Ions, sugars, amino acids, and other non permeable molecules cross via channels or transport systems)
What is a Volatile Anesthetic?
Volatile = being able to change from a liquid state to a gas easily
Small molecular weight volatile compounds
Administered as gases or vapors via inhalation
Most are fluorinated
Goals of Creating Fluorinated Anesthetics
Reduce or eliminate toxicity (metabolism)
Reduce or eliminate flammability
Allow more rapid induction and recovery from anesthesia
Properties of Nitrous Oxide
Synthesized in 1776
Currently used mostly as an adjunct to other agents to lower dose required for other anesthetic
Supports combustion (can serve as oxidant to fuel a fire)
Only anesthetic supplied in steel cylinders (gas at room temp)
Properties of Ether
1846
More potent than nitrous oxide
Minimal organ toxicity
FLAMMABLE (oxidizer)
Properties of Chloroform
1847
First halogenated anesthetic (makes it less reactive)
Pleasant odor
Nonflammable (due to the high degree of halogenation)
Properties of Cyclopropane
1929
Flammable
EXPLOSIVE under the right conditions (Ring strain increases its instability)
Properties of Methoxyflurane (Penthrane)
Methyl Ethyl Ether
Nonflammable, contains no preservative
Associated with renal toxicity (polyuric dysfunction) thought to be due to metabolism to release large quantities of fluoride ion (Plasma Fluoride >50uM = toxicity)
Properties of Enflurane (Ethrane)
Methyl Ethyl Ether
More highly fluorinated than methoxyflurane
More stable and more volatile than methoxyflurane
Releases much less fluoride than methoxyflurane, but more than halothane and desflurane
Properties of Isoflurane
Methyl Ethyl Ether
A structural isomer of enflurane
Widely used volatile anesthetic
Few problems of toxicity are associated with it
Properties of Sevoflurane
Methyl Ethyl Ether
Metabolized more than isoflurane, enflurane, and desflurane
Least stable anesthetic to soda lime or other basic CO2 absorbents
Rapid onset and recovery from anesthesia - similar to desflurane, but slightly slower
Properties of Desflurane
Methyl Ethyl Ether
More volatile than all other fluorinated anesthetics
Very stable and inert to metabolism
Differs from isoflurane by substitution of one fluorine for one chlorine atom
Rapid onset and recovery from anesthesia
Properties of Halothane
1956 The only ethane anesthetic Sweetish odor, nonpungent Prepared with thymol (preservative) Hepatotoxicity associated with it (Halothane Hepatitis at a rate of 1 in 30,000) - thought to be related to metabolism
Properties of Xenon
Chemical element symbol XE atomic number 54%
Colorless, dense, odorless noble/inert gas
First noble gas to be synthesized
Expensive
MAC 72
