week 2 Flashcards
a substance consisting of two or more elements combined chemically in definite proportions by mass
-pure substance
compound
when two or more elements combine to form a molecule, they always combine in a fixed or definite proportion by mass
law of definite proportions
a combination of 2 or more substances not chemically united and that exist in no fixed proportions to each other
-2 or more substances whose identities are retained and are mixed in the form of solutions, suspensions, and colloids
mixture
composition is uniform and every part of the solution has the same properties
homogenous mixture
components are not uniform throughout
heterogeneous mixture
can be an acid or a base
- extremely stable in temperature extremes
- universal solvent
amphoteric
physical properties of water (9)
- colorless, odorless, tasteless
- atomic mass of 18 amu
- covalent bonds
- bonds are bent
- high miscibility (mix well) with polar organic liquids
- high boiling point
- higher melting point, heat of fusion, and heat of vaporization
- solid form is less dense than liquid form
- high surface tension
chemical properties of water (3)
- amphoteric
- thermally stable
- can form hydrates and take part in hydrolysis reactions
separation of electrical charge
- hydrogen bond
- very strong bond
polarity
a hydrogen bond is also known as
bond
inorganic salts with water molecules combined into their structure in a definite ratio
hydrates
any group of substances that result from the reaction between acids and bases other than water
-form aesthetically pleasing solid crystals
salt
molecules trapped inside the hydrate
water of hydration
a substance that tends to absorb moisture from the environment
hygroscopic
the tendency to become a liquid upon standing
deliquescence
hydrated crystalline compounds that may spontaneously give up their water over time and become powders
efflorescence
a hydrate that has lost its water
anhydride
substance that does not contain any water
anhydrous
water is split and becomes part of the new product compounds
hydrolysis
high in minerals (calcium, magnesium, iron)
hard water
contains no minerals but does contain ions (sodium)
soft water
due to the presence of bicarbonate salts of calcium and magnesium (can be boiled to make salts insoluble)
temporary hardness
caused by sulfate and chloride salts of magnesium and calcium (must be treated)
permanent hardness
water solutions are also called
aqueous solutions
substance that does the dissolving (vehicle, most volume)
solvent
substance that gets dissolved (least volume)
solute
solute + solvent
solution
the amount of solute that will dissolve in a specified amount of solvent
solubility
able to be dissolved
soluble
unable to be dissolved
insoluble
two liquids that form a homogenous mixture
miscible
two liquids that don’t mix
-polar solutes dissolve polar solvents and vice versa
immiscible
- solubility depends on the physical and chemical properties of the solution
- do not have to be liquid
- solubiltity ranges from fully miscible to poorly soluble
solutions
- influence by degree of mixing, size of the particles, temperature
- process of dissolving may be endo or exothermic
process of dissolving
qualititative terms (5)
- concentrated
- dilute
- supersaturated
- saturated
- unsaturated
contains a large amount of solute
concentrated
contains a small amount of solute
dilute
solution contains MORE of the solute than it is able to hold
supersaturated
solution contains ONLY the amount of solute that it is able to hold
saturated
solution that has not yet reached the saturation point
unsaturated
quantitative terms (4)
- weight percentage (g/ml)
- ration (solute: solution)
- parts per million
- formaldehyde index
the amount of pure formaldehyde gas present in 100ml of fluid
formaldehyde index
properties of solutions (3)
- diffusion
- osmosis
- osmotic pressure
particles naturally move from regions of higher concentration to regions of lower concentration
diffusion
diffusion through a semipermeable membrane
osmosis
pressure applied to the solution with the higher solute concentration
osmotic pressure
properties of concentration (3)
- isotonic
- hypertonic
- hypotonic
two solutions of equal concentration
isotonic
more concentrated than isotonic
hypertonic
less concentrated than isotonic
hyptonic
types of solutions (3)
- crystalloid
- colloid
- suspension
a solute that can pass through a member
-particles <1 nanometer
crystalloid
a solute that can pass through filters but not membranes
-particles 1-100 nanometers
colloid
a solute that will not pass through filters or membranes
-particles >100 nanometers
suspension
embalming application (4)
- RBC membranes are semipermeable
- consider RBC in a hypertonic vs. hypotonic solution
- dehydrated cases
- edematous cases
substances that yield hydrogen ions in an aqueous solution
acids
substances that yield hydroxide ions in an aqueous solution
-highly regulated substances in biological systems
bases
pH shifts from ____ > ____ > _____ when a person dies
-acids, bases, and salts use water as their vehicles
basic > acidic > basic
any compound that can act as both an acid and a base in an aqueous solution
- water acts as base in the presence of acid
- water acts as an acid in the presence of a base
- when water molecules collide with enough force, a positive hydrogen ion can be formed
amphoterism
Acid produces a hydrogen ion H+ in aqueous solutions…. what results? (4)
- acids taste sour
- acids turn litmus paper red
- acids can exist as solids, liquids, and gases
- classified as strong, medium, or weak
bases produce a hydroxide ion (OH-) in aqueous solutions (3)
- strength of aqueous bases is determined by the percent of dissociation into positive ions and hydroxide ions
- strong bases usually dissociate in water and weak bases only partially dissociate
- some strong bases are referred to as caustic which means they are corrosive
- water solutions of bases may be referred to as “alkaline”
- titter taste
- bases turn litmus paper blue
- solutions of bases feel slippery or soapy
- bases generally exist as a moist or oily solid
acids react with bases to form a water and a salt
- base neutralizes the acid
- driving force is the formation of water
neutralization
- an acid is anything that accepts a pair of electrons
- a base is anything that donates a pair of electrons
lewis theory
the concentration of acid of H+ in an aqueous solution
-power or potential of hydrogen
pH
runs from 0-14
- pH less than 7 is acidic
- pH of 7 is neutral
- pH higher than 7 is a basic
pH scale
- cellular metabolism continues after death
- kindeys no longer work, creating an excess of metabolites.
post mortem pH shift
Basic > Acidic
post mortem pH shift
- proteins break down
- nitrogen is released into the body
Acidic > basic
Embalming chemicals function best in their optimal pH range
pH and embalming
formaldehyde 7.3-7.5
Glutaraldehyde 7.3-9.0
substances capable of maintaining a constant pH by neutralizing both acids and bases
-composed of a weak acid and its conjugate base or a weak base and its conjugate acid
buffer
any group of substances that result from the reaction between acids and bases other than water
salt
produce an acidic solution (still contain a portion of their H+)
acid salt
product of incomplete neutralization of a strong base and a weak acid
basic salt
all replaceable hydrogen components of an acids are replaced by a metal
normal salt
salt characteristics (2)
- ionic
2. ionization
salts dissociate into positive and negative ions
ionic
the dissociating of a substance into charged atoms or groups of atoms
-presence of ions allows for conduction of electricity
ionization